Hi mate,
Well i love playing as lh, but i played a lot as th so a few tips:
1) Ask your #5 to engage you as long as possible, lot of pressure there will help you.
2) Always point to the LH head, it's impossible to collide with his head (he will move it) if you loose the entrance as TH you will be screw. With this you will avoid crossing.
3) Try to engage your arm long and with your elbow move down his shoulder and then push him up using your neck.
4) If you are a newbie as TH, don't try to cross their hooker, try to open their LH.
5) Ask your hooker to put you forward him, like making a diagonal with the front row with you more forward than your LH.
Good luck!