Here's my current online setup. Not the pretiest, but runs shutoff valve direct to a moisture filter then to a 74 micron filter. I just like that that filter in the link can take 150psi and still filter to 10 micron.
I have seen a setup using a 3/8 pipe sleeve and cap both ends with threaded caps with adapetrs down to 1/8npt. Believe it or not they used a tampon for a filter!