Airspeed and attitude thats it. No more than 20 degrees bank. I sometimes turn a little early when I can be sure I'm not cutting anyone off because we use two parallel strips about 100 yards apart and it is not wise to stray over the centreline.
As a newbie ppl, I frequently apply a little more power on my turn from Base to final just in case, and I always flick my eyes down to the ASI and the ball in the middle of the turn just to check. By adding a little power I arrest my descent while I turn and avoid the temptation to pull the nose up when I start seeing the whites of the golfers eyes.
For a Cessna 172, over here we would have 20 degrees of flap and 70-75 knots on Base at about 1500-1700 rpm. Complete the turn onto final by 500 feet no more than 20 degrees of bank, then 30 degrees flap and 65 knots, gradually bleeding back to 60 knots at the proverbial FAA 50 foot tree on threshold.
Anymore than 60 knots with a 172 (with no headwind) and you will bounce. For a PA28 the only change would be Vref 63 knots.
Hope this helps. I would welcome advice on the subject.
Look up the Whitt's flying page as well.