Some brush modes have a mode percentage setting -
The effects you can get with Translucent, for instance, may very greatly per the mode percentage so it’s important to get it right in each case, and you can only do this with experimenting - up the percent 10%, make a stroke and see if you get what you want. No? Undo, change percent, and try again. Repeat this until you get the nice color blending you’re after.
I find myself doing this whenever using Translucent and Brightness. While these modes are very powerful and useful, needing to often change the percentage is a real bottleneck, in my case.
If changing the mode percentage was as easy and convenient as changing your brush size or color, it could drastically improve the effectiveness of the percentage using brush modes.
A way to increase/decrease the value without your cursor even needing to leave the canvas would be ideal - maybe holding certain keys and dragging up/down or left/right to alter the percentage. Something quick and on-the-fly.