You bought a new old house and once settled in you decide it is time to put your mark on the house. So you decide to repaint the master bedroom but upon close examination of the trim (windows, door, baseboard) you realize it is all screwed up. It looks like a previous do-it-yourselfer was the do-it-yourselfer from you know where. All the trim is either cross sanded, gouged, and/or all the edges have been randomly rounded over. If you are unlucky enough to find yourself in this situation what are your choices. A little hint, no matter what your choice, it will be a lot of work.
Your first choice would be to paint or repaint. If you choose this option expect to work your little butt off. Basically, what you will need to do is to scrape, mechanically sand, and/or hand sand the trim to make it look decent. All the scraping and sanding in the world is not going to make it look brand new. The intent is that when it is painted it doesn't look like you know what. You could strip the trim with a paint stripper prior to scraping and sanding however, unless you want to stain the trim this is a lot of work for little gain. If there is a lot of deep gouging in the trim the use of a filler of some sort would be highly recommended as paint will not hide anything that is that badly damaged. Expect to at least spot prime and then follow-up with two coats of a quality paint.
Your second choice, which in itself will be a lot of work, will be to strip the trim with a paint stripper (if there is a heavy buildup of paint sanding to a bare surface would be impractical) and scrape and sand until you achieve a near pristine appearance. If the trim is severely damaged wanting to stain it for that natural look would be more or less impractical and choice one or choice three would be your best options. However, if you trim is only moderately damaged, a lot of hard work will get you where you want to be. After stripping, expect to start standing with either 40 grit or 80 grit, depending on how severe the damage is, and follow-up with 120 grit, 180 grit, and possibly 220 grit. Once you have it sanded to near perfection then you can stain it (or leave it natural) and apply whatever final finish you desire.
Your third option, which probably involves the least amount of actual work, would be to remove the old moldings and replace them with either new stock moldings purchased at a lumber yard or home improvement store or custom milled moldings produced by a local millwork shop. This option would be the most expensive but would provide you with pristine moldings like what would have been present when the house was built. If replacing the moldings there are two options; if painting, paint grade moldings would be acceptable (they tend to be noticeably cheaper than clear molding) and if staining, you would need stain grade wood molding. Bear in mind, having identical replacement molding custom milled at a millwork shop generally can be very expensive unless you buy significant quantity.
No matter which option you choose do not expect to complete an average size room in an afternoon, it will take many afternoons. But as you can see in the picture, in which option number one was chosen, with a lot of hard work (and it was a lot of hard work) you can achieve excellent results.