Ok, Yamafreak here's my tips on the issue:
CF decal: In my eyes the easiest way for representing CF and it doesn't have to be bad at all. You have to find a type that matches and then get it there looking good. I tend to use a lot of Scale Motorsport "Plain weave pewter" in 1/24 scale but it's all in the eye of the beholder.
Mask the part to be covered with masking tape, trim the tape and move it to the CF sheet.
Cut it from the sheet allowing some excess around the edges.
Now, soak the decal in water and move it to a newspaper or such to get rid of excess water.
Cover part and decal with MicroSet and apply the decal.
Press it down with a damp cloth if it's possible, to get rid of any air caught benieth.
Now, put on a lot of MicroSol or something similar and go over the part/decal with your hair dryer. This last step can be repeated to get the decal to conform. Sometimes you get air bubbles, just pick them with a needle and put on more Microsol.
The hair dryer technique for CF is the best since it allows the decal to shrink in place.
After it has dried properly I paint the part with Tamiya smoke and then some clear to take the decal look away.
Mesh/stocking technique: In my opinion a choice between the two has to be made upon the complexity of the part to be painted. In both cases you need two sets of paint, one base coat (mostly a darker one) and a lighter color that will make the pewter visible. I tend to use semi gloss black as base and some metallic grey for pattern. It's really up to you to decide how the end result shall be, mabe use some brown/yellow combo if making kevlar?
The mesh will make a more subtle pattern, straight edged quadrants on a flat base. The mesh is more stiff though and harder to conform and therefor not that suitable for airboxes or such. The stocking on the other hand makes a more fuzzy pattern. You will see the shiftings in color but not in the same way as with the mesh. The pros with stocking is the conformity to an irregular surface.
When I've sorted that out I'll come to your question...
Trapping the part inside the mesh/stocking is the hardest part and the step where you can fail or succeed. You have to make a tight fit, but this is more important with the stocking as the mesh doesn't move around in the same way. I usually just wrap the part and try to get a firm hold on the back. If it's a very small part i use Blue tack on the back and squeeze the mesh in it. With stocking material you just try to get a tight fit and then pinch the stocking on the back and hold it firmly. If you spray directly from above it doesn't matter if the you have irregularities in the part, paint will go on in a strict pattern anyway.
Next step is to gently spray some greyish paint with low air preassure. You shall just pass the part a few times. Too much paint makes the end result look like crap.
Finally you remove the stocking/mesh...easier said than done as it is here you are able to be up for an major screw up...If it's a small part I just grab an edge of the mesh and let the part fall to the table. Larger parts I try to grab in an edge and quickly remove the mesh. If it looks like crap, just soak the part in windex if using acrylics and start over. Most often the result looks great.
I guess the major difference between stocking and mesh is the possibility to conform the stocking, In my eyes the mesh technique makes a better end result though. So my two cents after this long post is to try and use a mix of two or three techniques, depending on how the parts look. CF decal is as I said probably the easiest to get in place but the end result turns out better with paint.
best regards
Joel