Kung Fu Maintenance gives couple of tips on painting outdoors and painting curbs to keep them looking good video.
Painting Curbs Easy DIY Paint Tips
Here is a quick and easy tip if you are painting outside. Put your roller on the grass you can always cut the grass if the paint spills. If it spills on concrete or something your going to have a mess. It will be harder to clean up.
First make sure there is no paint on the arm of the handle. If you’re painting curbs you can just put your roller along the edge like so and roll it. That way you can use the roller handle as a guide. Nice and easy.