Like another poster I have difficulty swinging my leg over a trunk rack. What I use instead is a small waterproof pannier attached to the left side, this doesn’t seem to pose a problem mounting and dismounting. I don’t notice the imbalance when riding and it can hold all the stuff I need, along with a seat pack for tools and such. I have also used handlebar bags and they work well too but won’t hold as much as a pannier.
I used to use rack packs but the several I had always sagged or leaned left or right and the fastening system never worked well.