This question is very general, so it deserves a general answer.
It depends on the situation. There is no set-in-stone way to play a hand, it all depends on the situation (your position, blinds, stack sizes, tournaments or ring games, and # of people left if in a tournament).
Generally, I think raising with 88 in the early stages of a tournament to "limit the field" isn't the best strategy. You make money in the early stages when you hit your sets with mid-pocket pairs, not by bluffing out 1-3 people. Usually, limping or calling a small raise in a large, multi-way pot preflop is a sound strategy for playing a hand like 88. You want a lot of opponents in the hand, so when you flop a set you will usually get paid off (with a lot of chips).
Later in tournaments, this strategy changes. You want to start opening up more pots with hands like 88 and calling raises in position and playing postflop poker against 1-2 opponents. Unlike earlier in the tournament, you are not going to be able to see a lot of cheap flops with a lot of players. The pots are going to be more short-handed, so you need to adjust your play with different hands. Also, 88 is a solid hand when confronted with an all-in raise from a smaller stack, or when you need to push your stack in.
So, generally early in tournaments, you want to have large multi-way pots and you are playing solely for set value (95% of the time). Later, you want to be more aggressive with a hand like 88 and raise or re-raise. Again, this all depends on the situation.
In cash games, I believethe most profitable way to play 88 is to play for set value in large pots. If a lot of people have limped, don't raise, just limp in and hope you get to see a flop and catch an 8 and win a large pot. There are circumstances when you would want to raise, but it all depends on the situation.
For a specific answer, you need to post a specific hand...
I hope I helped.