I have been wondering what the best strategy is when playing from late position in some situations.

In the examples lets assume effective stacks are 35+ BB's.

lets say you are SB and a 30% opener opens at the button, which is capable of folding to 3betts.
you have QK,
do we 3 bett?

what is troubling me in these situations is that I always think
that my hand beats his range but when I 3bet I also fold out much of the
hands that i crush like JK,JQ,QT,Q9,KT, and only get called by the ones I'm flipping with or have us beat, and when we call we are just calling to peel.

IDK if this makes sense, maybe what I need to know is
what range are you 3 betting, and what are you calling from SB BB when a ~30% button opener has opened?

I think it is a good unwritten rule that you want to be 3betting your value hands (for obvious reasons) as well as (and not always)
1. Top of your folding range
2. Bottom of your calling range

All comes down to table dynamics
- how often is OR stealing
- how often is OR folding to 3bet and floating flops
- what is your table image

30% is on the smaller side for btn open. When V is only opening 30%, I would agree with you that his continuing range to a 3b is stronger than your hand, so I would not 3b, especially since if called we are OOP. Depends on the player but generally against an opener who's on the tighter side you're going to want to be 3b for value only.

What's wrong with just calling to peel when our hand beats his range? This is a good spot to be in.

Our decision to 3b or not should be based on our perception of his range and how much he folds to 3bets. For example, against V1 who opens wide and folds to 3bs a lot, you should 3b a fairly wide portion of your range. But against V2 who opens wide and continues wide to a 3b, you should just call with some of the marginal hands you 3b vs. V1. Against tight-passive V3 who folds to too many 3bs, you can 3b a lot despite that when you do get called his range crushes yours. Against V4 who likes to set-mine to an irrational degree and whose range calling a 3b is strongly weighted toward pps, you can take advantage of this leak by 3b a lot and c-betting a large percentage.

You may also factor in what parts of his range he continues to a 3b (slightly different from player to player) or how he will play 3b pots in general (how much he folds to cbet, for instance).

Regarding SB/BB, this does make a big difference. You should flat a smaller % from the SB because you may go to the flop OOP 3-way, and also you may open yourself up to a 3b from the BB. For these reasons, you should tend to want to 3b or fold from the SB much more than from the BB.

Hope that helps. I am no expert on this myself so hopefully some others will comment here.

thanks,I think this is what I needed.

I'm never 3betting here with a hand like QK!!! It is a good hand to play post-flop without spending too many chips pre.

3bets in this spot, in my opinion, are for really strong hands (something like AQs, AK, JJ+) AND some bluffs (things like 56, J3, etc.), hoping the villain will fold in this case.

If he never folds to a 3bet, than you should only 3bet with premium hands, but that's gonna make you easy to be read by a good player.