Stay safe & healthy
As a rule, stay away from public beaches, where tourists find themselves mugged any time of day or night. Most of the country has little crime, but Lomé is a clear exception, and is a good deal more dangerous than any city in Ghana or Benin. If going somewhere at night, take a car taxi, and get the numbers of a few trusted taxi drivers if you plan to stay for a while.
Driving is atrocious in Togo, with fatalistic overloaded speed demons chancing it on curves and hills, capital streets swarming with motorcycles throughout the black of night, and worrisome accident scenes along the main roads. The hilly north-south road north of Kara is particularly dangerous. If you are skeptical, take a day trip, and marvel at all the husks of buses and trucks that weren't there on the way out! Traffic is the single biggest danger to travelers in Togo.
Drink bottled water such as Volta or sachets of "Pure Water". Bissop juice is also fairly safe as it is boiled, and avoid the lemonade "citron" despite its delicious aspect. Stay away from road-side meals if possible. People relieve themselves in the streets in Lomé, so be aware of that.