I'd like to recommend reading "Living Wicca: A Further Guide for the Solitary Practitioner
" by Scott Cunningham. Chapter nine, Daily Prayer and Chants
, has some lovely, simple and effective prayers for several occasions. Personally, I'm a big fan of Cunningham, so I recommend him all the time.
He's a good author, so if you don't find the aforementioned book to your liking, you may like some of his other work. I also think that chapter eight of the same book, Effective Prayer
, might also be of interest to you.
From personal experience, I don't find memorized or rhyming prayer to be a necessity. When I was in a coven, we used specific chants and invocations. I wasn't able to memorize them at all during the short time I was with that group. It wasn't from a lack of trying, I did practice, but it just didn't work out for me. When I pray to the Lord and Lady, it's from my heart. I pray what's on my mind. To me, prayer is pretty much a normal conversation, treating the gods like a good friend. Imagine talking to Them like you would talk to yourself. It's okay if there's a bit of quick mumbling or a few pregnant pauses while your mind wanders briefly. They know what our limitations are as humans and They still love us.