1) Gently point out that Scotland isn't "going" anywhere, because it will retain the exact same geographical position after independence, and will remain firmly part of an island and cultural entity called Great Britain (barring the last-minute invention of that giant chainsaw).
2) If you form a suspicion that the person down the line is labouring under the "Madeley Misapprehension" that support for Scottish self-government must for some unspecified reason be motivated by anti-English sentiment, point them in the direction of this week's YouGov poll, showing that 65% of people currently planning to vote for independence have either a positive or neutral perception of England as a country. If your caller still refuses to accept that fairer and more equal structures of governance on these islands will be perfectly compatible with excellent (and indeed improved) neighbourly relations between Scotland and England, ask them to explain their reasoning, and then judge for yourself whether the response you receive has been properly thought through.
3) Politely seek to ascertain whether the caller is motivated by admiration for David Cameron and/or political support for the Conservative party. If the answer is 'yes', tactfully explain that while you respect their political convictions, such views are bound to detract from the relevance of any anti-independence arguments they might put forward, given that so many Scots primarily view the referendum as a once-in-a-lifetime opportunity to ensure that this country is never again ruled by a hostile Tory government that it did not vote for.
4) If the caller is unknown to you and proves evasive on the above point, continue to politely but persistently probe them on their personal and political background. If their responses remain vague, caution them that you strongly suspect that their motivation for making the call is loyalty to a London political party rather than a spontaneous need to declare their love for "the greatest political union in the history of the known universe", and that their anti-independence points are bound to be judged in that light.
5) If they turn out to be a Labour rather than Tory activist and they try the silly "please don't abandon England to the Tories" line on you, courteously explain to them that Scottish votes have only changed the outcomes of two general elections since the Second World War - in 1964 and 1974. You might ruefully point out in passing that our impact on the 1974 outcome was arguably undesirable in any case, because if Ted Heath had remained Prime Minister it's highly unlikely that Mrs Thatcher would have succeeded him, and the Tories would therefore have remained a much more moderate party. Explain that the Left can only really hope to flourish in England when it is seen as a comprehensively English movement, rather than one that has much of its roots in Scotland and Wales. Reassure them that independence will be a win/win outcome for the Left on both sides of the Tweed, with the near-certainty of no more Tory governments in Scotland, and a golden opportunity for a renaissance in the fortunes of English progressivism. Conclude by observing that there's certainly no point in both countries continuing to suffer together under Tory rule, as has been the norm for as long as anyone can remember.
6) If you become convinced that the caller is a London party activist cynically posing as a 'concerned member of the public', and if you're blessed with plentiful reserves of patience, you could do a lot worse than to simply keep them talking for hours on end, in whichever way you see fit. This will reduce the number of nuisance phone calls that other people receive.
7) Ask the caller if he/she supports the plans of all three London parties to abolish the Barnett Formula after the referendum, thus dramatically reducing the level of public spending in Scotland. In the unlikely event that they honestly and directly say 'yes', ask if they would support Scotland being granted full fiscal autonomy as a fair replacement for the current Barnett arrangements. If the answer to that question is an honest 'no', tell them that they have your respect, but they do not have your vote.
8) If the caller "loves Scotland" enough to accept that either the Barnett Formula must be maintained or that full fiscal autonomy must be granted, ask them to immediately write to their MP with a plea to that effect, and to send you a copy of the letter and of any reply that is received.
9) If they decline to express any opinion on the future of the Barnett Formula or full fiscal autonomy, don't allow yourself to be fobbed off with the line that "these are matters that can be decided later" or "that isn't really what this referendum is about". Remind them that anti-independence campaigners have based much of their case on predictions of economic doom and gloom, so it won't wash for them to now turn around and say "forget about your financial future, just think of the LURVE".
10) Ask the caller if their "love" for Scotland extends as far as a willingness to devolve sufficient powers for us to be insulated from Tory rule from within the United Kingdom, thus rendering independence somewhat less necessary. Get them to specify what powers they think should be devolved and by what date. Ask them to immediately send a plea to that effect to their MP, and to send you a copy of the letter and of any reply that is received.
11) If they're honest enough to admit that they don't support substantial further devolution to Scotland, and invite us to think of Tory rule that we didn't vote for as an unavoidable price to pay for London's "love", then tell them that they have your respect, but they do not have your vote.
12) Ask them if their "love" for Scotland extends as far as giving us a veto on whether nuclear weapons should continue to be stationed on our shores, and potentially putting up with Trident in their own backyards instead (if they can't accept that it should be scrapped outright). If the answer is 'yes', ask them to immediately send a plea to that effect to their MP, and to send you a copy of the letter and of any reply that is received. If, on the other hand, they're honest enough to say that they think unwanted weapons of mass destruction on our shores should be accepted as a price worth paying for London's "love", then tell them that they have your respect, but they do not have your vote.
13) If they pray in aid "that Team GB feeling", point out that it is quite normal for independent countries around the world to support the athletes of neighbouring nations at the Olympic Games, and that it is therefore highly likely that any Scot who currently takes pleasure in the achievements of Mo Farah or Jessica Ennis will continue to do so after independence. It goes without saying that we will continue to take just as much pride in the likes of Andy Murray and Kim Little once they are competing for Team Scotland rather than Team GB. What will disappear, however, is the mild fascism of the BOA that has resulted in the banning of Scottish flags at the Olympics, and the persecution of athletes such as Little who prefer not to sing a national anthem that they personally regard as alien. Ask the caller whether they regard the current situation as consistent with the claim that Scotland will enjoy "the best of both worlds" by rejecting independence. If they agree that it is not, ask them if they would be prepared to immediately write to the BOA demanding an end to the banning of Scottish flags, and to send you a copy of the letter and any response they receive.
14) If the caller keeps on telling you how much they "love Scotland", struggle against the temptation to ask if they agree with the chap on Channel 4 News who said that he wants Scotland to "stay" because it's the "most beautiful part of England". Instead, ask whether they accept that the UK government's threats to act vindictively against us if we become independent (for instance by trying to have us thrown out of the EU or attempting to deny us access to the shared asset of sterling) are incompatible with claims of tender feelings for us as a nation. If they do accept that, ask them to immediately write to Downing Street urging the Prime Minister to call a halt to these threats. Ask them to send you a copy of the letter and any response that is received.
15) You might also care to add that "true love isn't possessive".