I spin the seams.

I never seem to have a lump. I haven't made pinwheels for a while.

I spin my seams in the center. It may take a bit of trial and error but once you get it, it works every time.

Thanks everyone for your suggestions. I have tried spinning but doesnt' seem to work very well. I'm going to try pressing my seams open. Again thanks.

Thanks Onebyone. Good video

Watch this short and clear video, it shows exactly how to do it. Pay very close attention to how she presses the seams, especially with the HSTs at the very beginning. You DON'T want to press your seams open.
https://www.youtube.com/watch?v=VHKj542GDFI

Another one that shows the technique.

ttps://www.youtube.com/watch?v=gcqJmOJnkms

You should only have to pop a stitch or two for the seams to spin.

I spin my center and press. It works well for me

What do you mean, spin seams?

What do you mean, spin seams?

A poster has replied with link to what spin seams are and how to do them. There are many videos on youtube how to do it. I like to do the pop method.