A lot depends on the popularity of the attraction.
At DLR we normally get a FASTPASS to HM or IJA first thing in the morning. In the mean time we are able to ride
PotC, HM & either IJA or
BTMRR if not both in the first hour then start using the FASTPASS.
Newer attractions are going to run out of FASTPASSES before the day is over.
Often you will see a line to get a FASTPASS that is as long as (or longer than) the stand by line.
My advise would be to either get on those attractions first and/or get a FASTPASS for them very early.