How do you paint interior doors easily
Use a roller to get the most Paint onto the door, only for 1/3rd of the door at a time &amp; immediately Tip or Lay that area off. Tipping or Laying off is using a Paint Brush in the direction of the wood grain or simulated wood grain. Meaning, you even get the meeting joints perfect as well. You never want to just roller a door or trimwork, it looks horrible &amp; is a very obvious Bad Paint Job.

Only Paint the top &amp; bottom of the door if they've never been Painted &amp; then only after a Primer coat &amp; only every 20-years. They just need to be sealed but they don't need any regular refreshing that may hinder operation of the door.

Never Paint the locksets nor their latches, tape them or best is to spend the 1-minute it takes to remove them. If you don't want to remove the door &amp; the top &amp; bottom don't need Paint, then tape the hinges &amp; even overly tape them to trim the tape off with a utility knife. Priming &amp; Painting under the hinges, latch(es) &amp; inside the lockset holes should also be done once &amp; then every 20-years.