Coveralls/overalls

What’s the secret to getting these things sized correctly so they are comfortable 

Tried em on again today at the ranch store & just could not get them to fit right & they even had some cool insulated ones 

Willing to try them with a shoulder holster if I could just find comfortable ones & the wife stops laughing at me

I can't tell you how to do that but I've found bib overalls would pinch me in the crotch during extended drives.