Idiots guide to grow lights

I haven't sown anything tender yet this year. I've learnt by past experience that if I start off too early, I end up with far too much tender stuff indoors with tomatoes a foot high with no frost free place to put them. I will certainly be using my 'octopus' mid Feb/early March for tomatoes. I gave up on aubergines and peppers due to infestations of green fly, but maybe I'll give a couple another go but tbh the number of aubergines gained by growing my own don't really justify the bother.