There's no substitute for doing your homework - go and see nurseries/CMs, ask lots of questions, ask around for local recommendations, look at OFSTED reports. Then think about what suits your child. A shy/sensitive child might benefit from a quieter environment.
We chose our nursery because it has great local recommendations and the facilities/activities it offers are fantastic. The children looked really happy when we visited, the staff seemed engaged and affectionate. The food (made fresh by their on site chef) looked great.
I didn't want my dd going to the same playgroups etc that I'd taken her to on mat leave (lots of CMs took children to those). I knew she'd quickly become bored and she needed more variety/challenge.
Our nursery has structured/varied activities that suit dd. Yesterday dd rode a scooter and a trike, painted, played with play-doh, helped make biscuits, did singing and played games around learning letters and numbers. She's not even 2 yet. She loves going there, is always engrossed in something when I pick her up.
Don't fall into the trap of thinking all CMs provide constant, one to one loving care and all nurseries leave children to sit crying in their own poo. Keep an open mind, visit and get as much info as you can.