|You really don't need much in the way of accessories--unless you want them.
Something I hadn't even thought about at first was cloth wipes. They work better than disposable wipes, and make perfect sense if you are using cloth diapers. You can make up solutions, or just use plain water (what I do) and into the diaper pail they go. ME makes wipes, but I just use cheap baby washcloths. You can also just use cheap regular washclothes.
Besides that, all you truly need is a place to keep your dirty diapers. I think that something with a snug-fitting lid is good, esp. as baby becomes more exploratory (it's essential if you wet pail, to eliminate a drowning hazard), but some people do keep open pails. Just about anything will work, and there are lots of different things I've read here in the past--bit paint buckets, rubbermaid containers, step-open garbage cans, etc. I do have mesh liners for my buckets. They were especially handy when I wet-pailed and had a European front loader with a tiny opening. Now I have a North American one and can fit my whole pail in if I want (I have two smaller pails and keep one in baby's bedroom and one in the bathroom for rinsed poopies), so now I would consider the meshes non-essential. Still handy, and I do use them to lift and dump the diapers out, but not essential, esp. if you dry pail. My MIL made me some out of athletic mesh, in case you sew and want bags you can tailor to your particular container.
I know that one person here uses pillowcases to line her pails, and I think that sounds like a pretty good idea, too. But again, liners are optional.
When I wash the diapers, I rinse out the pail and squirt it down with vinegar, and that keeps it smelling okay.