Best way to enlarge spindle hole in vinyl records

Blackie is right. The tighter the fit, the better it is.
(Honi soit qui mal y pense)

Again: for heaven's sake be careful, if you MUST play the enlarging game, which inspite of what has been said above, I would refrain from. If you get the hole too large and you do not have a nice fiting contact between spindle and the LP you will get variable pitch, which you will certainly hear, especially on long drawn out notes. Also it would not do the suspension of your cartridge much good on the long run, adding more lateral strain to it than necessary.