You can use a step ladder with plank run to extension laddder that is placed on one step. There are also multi matic type ladders that you can set on the stairs to get access to the ceiling line. You can also use a painting pad on an extension pole but this does not get right up the ceiling line. In pinch, I will even use an extension pole with brush clip...brush basically attached to a pole so you can reach up high, but this is very hard to control and make straight line with.

The pros paint difficult spaces reqularly. They have learned to adapt using equipment available and have steady hands for cutting - even when using an extension.

For us DIY'ers we need other techniques. Call your local rental agent and ask if they have a Little Giant type ladder. Unlike a standard step ladder, both legs can have their length adjusted. They are perfect for working in stairways. Rental shouldn't cost over $20.

If the rental doesn't have one, or another solution for your need, call a pro. Be safe.

Thanks so much for the tips. I decided to paint the ceiling the same color as well, so I now I don't have to worry too much about cutting in perfectly. I'm going to try the extension pole w/ paint pad first, since it sounds the easiest and safest.
Otherwise, I'll look into renting the adjustable ladder; I had no idea such things existed.

Thanks again for the help, much appreciated as always.

We have a split foyer and I am terrifed of heights, so any kind ladder will not work for me.

The last time I painted I taped my brush to an extension pole. It was tricky but better than a ladder.