Turning downwind to base I take off power while banking to 45 degrees and pull back on the stick to bleed off airspeed to 1.3 - 1.4 VS while staying level.
Then add flap once below the speed to put them out -- newer pilots may want to be wings level before adding to the workload.
Trim on base once flaps down if not before.
Turning base to final -- 45 degrees is good.
If you're undershooting the turn you can take off some bank, but lets not be adding bank past 45.
Turning final, you do not want to be bleeding off airspeed as there's not much to give away; so, it's a descending turn with much less back pressure than turning base.
45 degrees gets the turn done efficiently and gives any X-wind towards the runway less time to blow you past final -- a wider downwind may help in these conditions -- no point making it harder for yourself when it's like that.
Shallow turns lead to the temptation to help it around with rudder and get yourself in a spin.