If your not happy with the finish do it again, even I sometimes do a room, and there could be just the one wall that dont look right, and I will do it again, I have done the same on the other walls, but for some reason one wall isnt as good, so I do it again.
Dont dab here and there, do the whole wall again, cut in top and bottom, and the sides, then roll into it, so you dont get that cutting in edge, but, when you come to rolling into the cutting edge bit, dont heavy roll that bit.
I did an apprenticship, and I learned a lot, and passed my C&G, but it wasnt until I was working with the old boys and they passed on little tips, that I actually learned the proper way of painting.
One old boy told me to cut in with a 1" brush at the top, I laughed at him, until he explained why, that you dont see so much of the actual brush marks with a 1", I did do it, and it was better, but took ages, and then would go on to cut in with a 3 or 4" brush, and then would work the roller very gently up into the cutting in to get rid of the brush line, but I would do it quite thinly, then roll as normal.
If you have a ridge already with the cutting in, and you want to paint the whole wall again, then rub down the ridge bit, cut in again, then do like I said above, and you should be fine.
I hate when people say 'if you can pi55 you can paint', yes thats true in a way, any one can paint, but painting a perfect wall is an art, and comes with practice and experience, there are so many factors to consider, your roller, what paint you use, how much thinning, how quick you are, and of course what are your walls like.
This is why on my final coat, I cut in and roll one wall at a time, and you will get a much better finish all round.
if you have to paint the walls agin, and your skirtings is already been glossed etc, just be careful you dont get any splashes on then and if you do wipe off.
The trick is in this situation is to wet your skirting first with a cloth, not a damp cloth, but quite wet, then paint your wall, then wipe your skirtings again, the first wet, stops any blobs or drips from settling on the skirtings,and the last wipe just makes sure that none have stayed there.