I'd probably just use a roller honestly.
I am a not-terribly skilled decorator. My conclusions are as follows:
Buy branded frog tape, the delicate version. Accept that doing the taping is going to take pretty much as long as the painting will. Ideally give the room a couple of days to dry before you try and do the skirting boards at the end but meh I usually can't be bothered to be faffing about with my furniture that much.
If I had an ideal room painting set up it would be:
Day 1 - Prep the walls (sugar soap etc). Paint the ceiling.
Day 2 - nothing.
Day 3 - tape the ceiling edges carefully (on the ceiling side), preferably do the skirting boards too unless you're painting in a light colour. Do the cutting in first. Then roller the walls. Give it a few hours, second coat.
Day 4 - nothing.
Day 5 - tape the bottoms of the walls and paint the skirting boards.
Done.
In reality I don't usually do that because I'm usually scrambling to get it done in a weekend, but that makes taping much harder because the paint is more delicate. The frog tape is pretty good but it's not perfect and you can end up taking your newly rollered paint off again if you aren't super careful.
Experienced decorators would say you should just cut in (paint the edges) without taping, and I do sometimes do that but I am really just not very good at it, so I generally tape everything up where possible.
Remember to unscrew the door handle if you're painting the door and to unscrew the light switches from the walls. If it's the bathroom remember to take the toilet cistern top off.