So guys, i had a great day talking with a painting contractor and as  an expert Saint Louis painting contractor. Am sure he’s nuggets are premium and i want to share with you;

Roll the full height of the wall and keep a wet edge so as to avoid lap marks.

Lap marks are unattractive stripes usually caused by uneven layers of paint buildup. This usually occur when new paint is rolled over an already painted area that is partly dry. To avoid lap marks, maintain a wet edge, so that each new stroke of your roller partly cover the previous stroke before the paint begins to dry.

In order to maintain a wet edge, start painting near a corner, run the roller up and down the whole height of the wall, moving over slightly with each stroke. Wherever necessary, move backward to even out thick spots. Make sure not to let the roller become nearly dry, reload it often so that it is always half loaded, at least. Also, ensure that the open side of the roller frame is facing the area that is already painted so as to put less pressure on the open side of the roller which makes it less likely for you to leave paint ridges.

Mix various cans of paint in a large bucket to ensure a consistent color throughout the room.

The color of paints may slightly vary from one can to the other. The difference may be noticeable if you have to open a new can of paint in the middle of a wall. If the paints are mixed together, it eliminates this kind of problem. The best thing to do is estimate the amount of paint you will need and then mix it in a large bucket. When estimating, add more rather than less to be on a safer side. The left over can always be poured back into the cans. If the job is large, use the bucket and a roller screen instead of a roller tray. It is much faster to load roller with the screen than using a roller pan.

Allow the paint to dry and then cut the tape loose for a perfect edge.

When the paint is dry, it is not advisable to just pull the tape off the trim. Usually, paint forms a film between the wall and the tape. Removing the tape tears pieces of dried paint away from the wall. Therefore, cut the tape loose before pulling off the tape. When the paint is completely dry, a sharp utility knife should be used to slice through the film. A mess will be made if you cut the while it is still gummy.