Injection site issues

Having had to have injections for over 61 years I would like to ask if any are like me and have a few problem areas with their sites.

For too many of those 61 years I didn't really give any notice to my injection sites and as a result the tops of my arms have suffered more than anywhere else as it was always easier doing my injections there. Even after not using these areas for some time they are still crowded with lumpy and bumpy bits.

Have you had any issues with this, if not can you please let me know what you might have done to avoid it?