I would recommend using suntan lotion if you're fair skinned.
Toiletries and Medical Supplies: I used Autan bug spray on myself in the evening and didn't have any problems.
I note that even with a nightly spraying (provided by hotel) in our room and closed windows the little devils would get in.
I took malaria pills (Larium) once a week on the first trip (2 weeks) and didn't have any problems. Didn't take anything on the second week long trip and was OK. However, my brother has informed me that malaria is like herpes, only between you and the mosquito. It never really goes away.
It's sandy everywhere and most of the women/girls I saw wore flip flops. I like sandals with a bit of height since the sand can be a couple inches deep.
I'd recommend a light overshirt for sun protection if you're fair skinned.
If you'd like an outfit in the local style have it made in Cotonou. The cost is much better than what you would pay in Italy or the U.S.--where I have inquired. There are many stalls with fabric in the main market. There's a pricier specialty store near the shop where a huge line forms to buy bread. Have to find out what the address is. Word is cotton fabric from England is better than that from the U.S. I think you have to see and feel for yourself.