I tried tucking several times in younger days but ran into many of the common frustrations...
The pain, becoming aroused, things not staying in place... Not satisfied with my appearance
One day while thrift store shopping, I came across a pair of somewhat worn but not worn out pair of Levi's 501 jeans... Wow! In my size no less!

Holding them up for further inspection I noticed that these jeans had obviously been worn by a rather tall woman who wore her jeans rather snug
I thought... "Oh if only my jeans would make that shape"... Then the bells and whistles went off in my head... Right there was my template
It didn't always go perfect, but those "pre-formed" jeans held things in place rather well most of the time
Well, tucking has become much easier now (Mr. Happy rarely ever gets aroused) and years later I still have those jeans and my new jeans make that shape after some wear even though I am still pre-op