I make all my Synthweaving money off of orange and purple gear I make.
I lucked out, I am lvl 34 and my Synth skill is around 320 and I have roughly 8 different orange schematics and 2 purple.
The orange I either got as drops, or my crew returned with from missions (sorry, can't recall any of the missions, I was usually to busy giggling as I got my orange to care)
Purple schematics are very rare, but there is a way of trying to get them. Keep making and reverse engineering your gear. there is a low chance (about 20%) that you will get a blue, better version of what you made. There is an even lower chance of getting a purple (I don't know if reverse engineering blue equipment increases this or not).
Anyways, when you finally get good equipment you can make, make a few and start selling them on the GTN. First, look up similar items (or exactly the same item) to see what others are selling them for, then set the price a bit lower for a better chance of selling them.
Synthweaving is an expensive buy in, but it starts to make money once you have the better schematics and lots of built up materials.
Hope this helps!