So you want to freshen up that door....

Let me just start out by saying that its not always that easy depending on ones situation.  Here are some tools you'll need for painting a door with latex paint: A 2 or 3 inch professional brush, a 3 inch mini roller, a roller grid or pan, 120 or 220 grit sand paper (depending on roughness), blue painters tape, a small drop cloth, a rag, and primer (depending on your situation). 

Now that you have the tools, you need to do as follows:

1. Lay out your drop cloth. 

2. Sand and scrape the surfaces to be painted. This not only gets it smooth, but it promotes adhesion. (You may not need to scrape)

3. Wipe off the dust with a damp rag. 

4. Tape off anything that you don't want to get paint on such as hinges and door knob etc. this especially helps when it is hot and you need to work fast.

5. Apply a latex primer for any bare wood areas to seal them. You may need to apply an oil based primer if the previous painter has painted latex paint over top of an oil based paint(latex paint does not adhere to oil based paint). To test for this simply scratch the door with your nail. If the paint comes right off then you will need the oil primer (oil based primer requires an oil based brush)

6. Now you are ready to apply the finish coat. 

A. If you are doing a multi panel door, start out by doing the panels first. Then everything else. 

B. If you are doing a completely flat door use your roller and go to town(you may need a larger roller depending on the size of the door). 

C. If you are doing a door with any glass always do close to the glass first then the rest using your roller. Here is an example of a door I recently did: 

As you can see since I was painting the door red again I hit the bad areas with a gray primer. This is the only color primer one should use for red. Then I proceeded to spot paint over the gray areas with the new red paint. This could save me from having to do extra coats.