How can i get the most out of my clones?

I have 18 clones and 4 seeded plants that i planted about a month ago. I put them in about a month late but so far theyre all doing very well, some are about 2 and a half feet tall others are reaaallly bushy and have like 5-8 tops. I live in southern Ontario (613 area) and last year I remember my crop was flowering about this time of year, and this year's grow has nothing so far. Ill get some picture up here soon.
Anyways I really want the biggest yield possible for my 24 plants and was hoping somebody could give me some tips.