But I love giving it to willing ladies and have gotten fairly good at it too. Preparation by a small plug, plenty of anal-specific lube, angle of insertion, and the position the lady takes to recieve it are the key to insertion without hurting her.
Also, a little known fact is sticking it in balls deep is not the end of the story; you can't just commence to pounding the ass. Porn gives people the wrong idea about that.
The sphincter actually wants to push the dick back out so if you start trying to slide it near all the way out and put it back in whats going to happen is once you pull it most of the way back out those muscles are going to eject your dick and you'll be back at square one and probably end up losing your hard on for how much you'll have to focus on getting back in.
What you do is you work your cock all the way in slowly and gently to the balls, then you do short strokes. Real short strokes gently.
You will begin to feel her sphincter relax more and more until eventually you will be able to do those long strokes everyone likes, and if you pull it out at this point you will be able to push it back in far easier but still be gentle and considerate with insertion; you can be a little rougher once you're already in.
Stimulating her clit with a vibe while you fuck her ass like I've described is a sure ticket to squirt-town 👌🏽