One thing to remember when using any GPS is that sometimes the directions may not be correct so always be sure to look at the road signs before making a turn.

OSMAND as an example sometimes doesn't see no u-turns. So make sure to read the road signs and not just follow the GPS blindly. A solution to this error of Osmand is to use the online routing(cloudmade) service it has to calculate the route. I found the online routing service to be more accurate than the offline one Osmand has. Since it only uses the data connection when calculating routes, it uses less battery power than waze which has to constantly download info from the web.