205-315pnds on the bar so at the bottom of the press where chest assists its lighter, then as you press up to the top where its mainly tricep you want 405-500pnds.
Tris are one of my weaker muscle groups. I have added a lot of volume over the past few months (start with close grips usually) and found some success. Try adding a second light day where you hit your tris during the week.
I always lived by the HIT low volume motto and I found upping the volume works much better than me. There is no one-size-fits-all solution.
Weighted dips ares superior for triceps IMO.. heavy, below parallel, elbows tucked... love em.. and skullcrushers, and if my split involves an arm day, cable v bar push downs