The roller is a very good way of managing to paint a large area, however, the ends of the roller can produce ridges which spoil the evenness of the paintwork.

In order to avoid these roller marks, below are the methods i came across in BRS Custom Painting, take the time to use the methods which will allow you to avoid it.

Get Some Good Tools

The best way to keep your paint roller from leaving marks on your wall is to buy the best. Purchase good quality paint of the sort you need to complete your project, gloss or matte paint perhaps.

Also, take the time to buy a roller which is average or good quality as a cheap roller will probably not do as well.
To keep the paint from streaking at the edge, look for a roller which has a beveled edge and a suitable core.

Cheap rollers do not have these features and their core is usually made from cardboard. It will get damp during painting, loose the shape and then cause more marks.

Mix Well

After getting your paint, start by mixing the paint thoroughly. To get the paint parts mixed together, use a metal stir stick. This will help you to avoid streaking and unevenness.

There is more chance of creating bad paint roller marks if the paint is not mixed properly.

Paint the Edges

Now, take the paintbrush and cover in the first two inches around the edge of your wall. Doing this will help in avoiding marks caused by trying to force the roller into the corner.

Apply Paint Evenly

Start using the roller by spreading a layer of paint out into the paint tray. Put the paint roller into the paint, then roll out into the tray till you have an even layer of coverage.

Try to avoid getting the ends and the core soaking with paint because this will cause them to leave roller marks. Put the paint roller onto the wall and roll it upwards and downwards with long even stokes.

Make sure you paint at a slight angle so that you are not leaving straight marks. Also, blend the next stroke into the old stroke, repeating the angled shape. Do this until the wall is complete.