I really enjoy stretching and going deep. I really started with stretching in only the past 5 or 6 years. I have several dildos 2.5" in diameter and one that is 2.75" in diameter. None of them are a problem. I have several toys 1.5" and 1.75" in diameter. Naturally they are not a problem to insert fully (2 of them up to 18" long). What I also like to do is double insertions with any combo of these smaller diameter toys. I'm fairly certain I could take a woman's smaller fist; but, don't see that ever happening.
I mentioned in another thread a few weeks ago when I finally bottomed out on a 2.5" x 13.5" (insertable length) dildo I found out I'm a moaner. Anyway, I have a 12" double header fully up my ass about 50% of the time as I like to head off to the bathroom regularly to fuck my ass with it. I also like to have it about 1" out of my ass at night so I get a bit of stretch for 6 - 8 hours overnight. Often times I will press/massage my stomach by the end of it as I slowly push it about 1/2" out of my ass and then push it back in by squeezing my anus muscles.
Today I enjoyed a new adventure. We purchased a winter home last year and spent the winter there before returning to our summer home the end of April. Well, we just came back to the winter home for a week and went to the complex's pool today for the first time. There I was in the pool fucking my ass with the double header. A guy can do that when nobody else is in the pool. I'm looking forward to going back to the pool in the next day or 2.
I tried a banana once and it was just too messy. My favorite food insertions are seedless white grapes and hard boiled eggs. So long as I am well cleaned out, I'm happy not to waste them as I will eat them after removing them. Once, while my wife was gone for a few days, I used a cucumber and could do that regularly if I could figure out how to explain to her why I wanted cucumbers when we don't normally have them in the house.
My advice for enjoying anal insertions would be to go slow, start small and increase the size as you can, and use plenty of lube. However, I would add to not just insert whatever it is but to also grab hold of it and literally fuck your ass with it as in: in-out-in-out and repeat often.