Fine Detail Painting

+1 to what Don and Snibs said.

I have a bunch of different brushes for different tasks; in different sizes and thicknesses.  And I've been known to trim down a brush to make it fit a specific task.

And I'll mask areas if I think I have the propensity to be "excessive."

I find those corners a good candidate for the thinner widths of Tamiya masking tape.  Also, for fine detail painting I use the tip of a sharp  toothpick, which is finer than the finest brush I have.  Takes a lot longer 'cause it doesn't hold much paint, but then again that is the reason it works so well.  I shake my bottle of paint, take the cap off and lay it down upside down.  That leaves the perfect amount of tape covering the cap so that I dip the toothpick end in (vertically) and it picks up just the right amount for fine painting.  Good for switches, small controls, etc.

I like to grip the paintbrush as close to the bristles as possible. I usually grip the ferrule. This gives me more control. There is probably some geometric or mechanical explanation for the extra control, but I don't know what it is called.

Ditto on the above and also the right good quality brush is always a bonus, there not cheap but you will never regret getting a good quality brush, a chisel shaped flat would be best for flat line work including 90 degree. Thinning paint is always the way I go as well with Humbrol enamels, I don't like there own thinner as much as normal gp or enamel thinners but that's just my opinion. Also a hobby knife or a cut down razor blade can be handy in some circumstances for corner work and use it exactly as you would painting a house with a scrapper, old PE frame can do well too. Most of all is practice practice practice, there's no substitute for experience.

Mick..

Don't be afraid to use dissimilar paint types. Have an acrylic base color, and once that has dried and cured use enamels for detail work. Any excess can be removed with a thinner moistened brush to deal with those errors.

DWood538

I've been working on the ejection seats for my F-15E recently, and I have discovered I need some help with hand brushing the fine details such as the molded in seat belts and head cushions. I feel that I'm doing very good for this being my first serious model, but I know I can still improve, so I'd like to hear some tips or techniques that you all have found to be helpful. If you know of any good articles or posts on the subject, I would be very interested. Particularly one thing I have found to be a challenge is painting in a 90 degree corner, because when I brush into the corner from one side, the paint likes to jump to the other side, ruining the fine edge I hoped to achieve (I'm using Model Master Enamels in case that is a factor). Any and all help would be greatly appreciated, I've seen plenty of your cockpits, and I know you guys must have some great tips.

Couple of ideas

1- keep your brush "flatter"( more parallel ) on the painted side to avoid having the "outside" of the brush touch the "wrong" side 

2- watch for static electricity that will literally pull the paint off the brush 

3- take a deep breath let 1/2 out and hold the rest and touch the brush to surface ( guys that fire guns know this trick; it can steady your hand for a short time) NOTE: If you feel faint or are getting blurry vision  you have held your breath too long. So breathe at this point or  a bit before,

for best results