I let the beer sit in the primary 1-2 weeks after it reaches FG. 1 week for low gravity beers, such as milds and ordinary bitters; 2 weeks for medium gravity beers, such as pale ales, ESBs, porters. Then, rack to the cubitainer or winpack. Add enough sugar (3-4 teaspoons per gallon, IIRC.) for the yeast to bring it to 1 volume of carbonation and maybe finings.
Let it set at about 55F degrees, for the yeast to carbonate. (When using the cubitaner, the spigot will need to be upward.) If 55F isn’t possible, room temp is OK. The cask will swell. That's OK and necessary. You’ll need to monitor it and maybe release a little gas if it looks like the sucka is gonna explode.
Once it stops producing gas, release some so that it’s not under too much pressure and turn the cask so that the spigot is down. Keep cool and don’t move it for a few days. During this time, the beer is absorbing the CO2 and dropping bright. You can take a taste or three during this time.

just to make sure everything is going alright.
Serve @ 55F if at all possible.
When using the winpaks, the spigot is down and the other hole is up. When dispensing, open the small hole. You’ll have 3 or 4 days to drink the beer. The cubitainers collapse on themselves as they go... they don’t allow O2 in, so the beer can last longer. The only thing- you don’t get the additional flavors that are part of the appeal of cask ale.