1. Find a saddle you (and yr junk) likes.

2. Adjust (fore/aft) and level saddle for efficient peddling.

3. Select a stem length that gives you a comfortable reach.

4. Consider different bar widths and bends for comfort in all positions.

Nailing fit can take some time and some fiddling around. Additionally, your fit will change with age and years on the bike.

Core strength, stretching, and yoga all help.