Upwork has refined the art of connecting freelancers and clients quite well -- they've created a space that feels both secure and yet wide open to possibility. They put a lot of focus on insuring freelancers' genuineness, which can be an annoying number of ID verifications, but *breath* and remember it's as much for my good as theirs. I've been freelancing through them for nearly six months now, and it's been great so far and looks promising for future development.