biggest tip that i can't emphasize enough is transplant established seedlings ( cs females for me) with a deep root-ball at the earliest time possible without inducing premature flowering. this requires some experience to get the timing down.
Couldn't agree more... The right size seedling stripped of most leaves and buried up to its neck at the start of the season is key for the extra vegging you want to occur to support a massive bud growth come the end of the season. I think the only way to achieve the big results on the east coast is to make big holes and plant well rooted seedlings/cuttings at the exact right moment in the season. I had one plant start to flower when it was only planted 5 days ahead of another, which took off into veg mode without any stress.