Tolu is my favorite sleepy Colombian beach town. Very peaceful, uncrowded even during so called busy periods and Colombian holidays. By far it's the most economical and laid back beach town I've ever experienced. A great place to relax, eat beach food and to count your blessings for life.
I recently traveled from Bogota to Tolu. Although car rental is very costly, it's well worth the price to travel through Colombia. The trip takes about two-and-a-half days, but wow, what fantastic views. Stopping every night in a hotel along the route -- no problems and low cost -- it's very safe these days. We found the best beach was San Francisco Beach -- very clean and good service with beach umbrellas and good food. Tolu is now undergoing a tourist boom and prices are half the price of Cartagenia. Also French Beach is nice and the walk along the beach is superb. You can also go on a power boat trip and visit a few small islands -- have lunch and enjoy the Caribbean at a modest cost. Go now before prices start to increase with tourism. Make sure you take a bike taxi -- the drivers are fun and they know everything.