There is no rule which says you must paint woodwork white, or strip it, or color it to merge with the walls.
In a room whose walls, window frames and doors are in the same neutral color, you could paint the skirting board a clear contrasting color. This will define the line between the floor and walls. Trim colors that contrast with walls and ceilings might suit your style in one room, while a more subtle color change might be right somewhere else in the house.
You can liven up plain, flat walls by adding moldings so as to create panels around the room. For best results, make sure you keep your working area within the proper temperature range recommended for the paint.
All interior woodwork that has been stripped, from baseboard to dining room tables, needs to be primed with either a standard acrylic wood primer. After that you can paint on it with oil-based flat eggshell, gloss, or acrylic paints.
Most interior woodwork looks best in an eggshell finish, as high-gloss paint can have a rather bleak, deadening effect. If your plan is to paint walls, ceiling, and trim, then it’s best to get the trim painted first, along with the room’s windows and doors. Paint woodwork in small sections. Keeping a wet edge to avoid lap marks.
A wide range of broken- color effects work well on woodwork, but ideally you should use oil-based paints as latex has little durability on wood. Stains add color to wood while allowing its natural grain pattern to show through.
Varnishes are clear finishes that form a tough coating over stain. They are available in a range of finish sheens from satin to high gloss. At the end of a project, combine all of the leftover paint of the same color into as few cans as possible.