Any tips for this?

It's tough to say. It really depends on your opponent.

In general, you want to mix up your play.

I'll frequently 3-bet 3rd if I have the better doorcard. I play low stakes HU SnG's frequently and it gives me a better idea of their hand ranges. I tend to do this more often with 3 straights and 3 flushes since it gives me the odds to chase on later streets.

I tend to raise the other guy's bring-in frequently.

I get a lot of action on my big hands because of the above two things, but I limp as much as I raise and 3 bet.

Here's a few bad examples of 3-betting, since the guy raised his bring-in on every hand but one:

Full Tilt Poker Game #5842507956: $10 + $0.50 Heads Up Sit & Go (44478143), Table 1 - 30/60 Ante 5 - Limit Stud Hi - 14:10:35 ET - 2008/03/30
Seat 1: Loxstar (1,500)
Seat 2: Studinator (1,500)
Loxstar antes 5
Studinator antes 5
*** 3RD STREET ***
Dealt to Loxstar [6d]
Dealt to Studinator [7c 5c] [8s]
Loxstar is low with [6d]
Loxstar completes it to 30
Studinator raises to 60
Loxstar calls 30
*** 4TH STREET ***
Dealt to Loxstar [6d] [8c]
Dealt to Studinator [7c 5c 8s] [2s]
Loxstar checks
Studinator bets 30
Loxstar calls 30
*** 5TH STREET ***
Dealt to Loxstar [6d 8c] [Jd]
Dealt to Studinator [7c 5c 8s 2s] [4c]
Loxstar checks
Studinator bets 60
Loxstar calls 60
*** 6TH STREET ***
Dealt to Loxstar [6d 8c Jd] [Kd]
Dealt to Studinator [7c 5c 8s 2s 4c] [Jc]
Loxstar bets 60
Studinator calls 60
*** 7TH STREET ***
Dealt to Studinator [7c 5c 8s 2s 4c Jc] [7h]
Loxstar bets 60
Studinator calls 60
*** SHOW DOWN ***
Loxstar shows [Kc 6s 6d 8c Jd Kd 4s] two pair, Kings and Sixes
Studinator mucks
Loxstar wins the pot (550) with two pair, Kings and Sixes
*** SUMMARY ***
Total pot 550 | Rake 0
Seat 1: Loxstar showed [Kc 6s 6d 8c Jd Kd 4s] and won (550) with two pair, Kings and Sixes
Seat 2: Studinator mucked [7h 7c 8s 2s 4c Jc 5c] - a pair of Sevens

Full Tilt Poker Game #5842554086: $10 + $0.50 Heads Up Sit & Go (44478143), Table 1 - 30/60 Ante 5 - Limit Stud Hi - 14:14:29 ET - 2008/03/30
Seat 1: Loxstar (1,350)
Seat 2: Studinator (1,650)
Loxstar antes 5
Studinator antes 5
*** 3RD STREET ***
Dealt to Loxstar [Qh]
Dealt to Studinator [7d 4c] [Ac]
Loxstar is low with [Qh]
Loxstar completes it to 30
Studinator raises to 60
Loxstar calls 30
*** 4TH STREET ***
Dealt to Loxstar [Qh] [2c]
Dealt to Studinator [7d 4c Ac] [4s]
Studinator bets 30
Loxstar calls 30
*** 5TH STREET ***
Dealt to Loxstar [Qh 2c] [Jh]
Dealt to Studinator [7d 4c Ac 4s] [5d]
Studinator bets 60
Loxstar calls 60
*** 6TH STREET ***
Dealt to Loxstar [Qh 2c Jh] [9d]
Dealt to Studinator [7d 4c Ac 4s 5d] [6s]
Studinator bets 60
Loxstar calls 60
*** 7TH STREET ***
Dealt to Studinator [7d 4c Ac 4s 5d 6s] [3d]
Studinator bets 60
Loxstar calls 60
*** SHOW DOWN ***
Studinator shows [7d 4c Ac 4s 5d 6s 3d] a straight, Seven high
Loxstar mucks
Studinator wins the pot (550) with a straight, Seven high
*** SUMMARY ***
Total pot 550 | Rake 0
Seat 1: Loxstar mucked [Js 8c Qh 2c Jh 9d 6h] - a pair of Jacks
Seat 2: Studinator showed [7d 4c Ac 4s 5d 6s 3d] and won (550) with a straight, Seven high


Full Tilt Poker Game #5842585939: $10 + $0.50 Heads Up Sit & Go (44478143), Table 1 - 40/80 Ante 7 - Limit Stud Hi - 14:17:12 ET - 2008/03/30
Seat 1: Loxstar (990)
Seat 2: Studinator (2,010)
Loxstar antes 7
Studinator antes 7
*** 3RD STREET ***
Dealt to Loxstar [8c]
Dealt to Studinator [Jd Ad] [8s]
Loxstar is low with [8c]
Loxstar completes it to 40
Studinator raises to 80
Loxstar calls 40
*** 4TH STREET ***
Dealt to Loxstar [8c] [4c]
Dealt to Studinator [Jd Ad 8s] [Ks]
Studinator bets 40
Loxstar calls 40
*** 5TH STREET ***
Dealt to Loxstar [8c 4c] [7h]
Dealt to Studinator [Jd Ad 8s Ks] [Jc]
Studinator bets 80
Loxstar calls 80
*** 6TH STREET ***
Dealt to Loxstar [8c 4c 7h] [5d]
Dealt to Studinator [Jd Ad 8s Ks Jc] [Ah]
Studinator bets 80
Loxstar calls 80
*** 7TH STREET ***
Dealt to Studinator [Jd Ad 8s Ks Jc Ah] [Jh]
Studinator bets 80
Loxstar folds
Uncalled bet of 80 returned to Studinator
Studinator mucks
Studinator wins the pot (574)
*** SUMMARY ***
Total pot 574 | Rake 0
Seat 1: Loxstar folded on 7th St.
Seat 2: Studinator collected (574), mucked

Concentrate on pairs and high cards. I used to play a lot of Hu stud 20 years ago - play your board strongly as well to get your opponent to fold.
As drcossack says, it's opponent-dependent. Raising 3rd is standard with playable hands...

HU stud, as with HU variants of other games, is all about getting a feel for how many bets mean what sort of hand from whatever opponent you're playing. that sounds extremely simplistic, but it is the absolute key for HU games. basically, bet and raise with seemingly reckless abandon until your opponent becomes predictable (did he put in 3 bets on third? he has any pair. did he raise 5th? he has 2p. did he just call 5th? he has one pair. etc, etc). virtually any opponent worth playing will become predictable in this regard if you start off with seemingly donkish aggression, and once that happens, just maximize value when you're ahead and draw at a winner when it's profitable to do so. you'll crush.

checky's post gives you a good idea of how to read the opponents and make good decisions.

Good post. I've actually been playing a lot of HU and SH Stud8 lately, .50/1.00 and lower. Lots of fish sit in short and go busto and the decent regulars who play full ring don't adjust well. I just sit out when we get 5 and start a new table.

I may even give HU Stud Hi a try, which I hate and suck at full rng .

Yea I like to mix up my play in HU.. obv don't have to play near as strong of hands. Pay even MORE attention to your opponents cards also.