Go across with some buds...and now big MF'ers of course...and go with a girl if at all possible it does not look as obvious. Get the stuff you need, first you gotta find the vet sometimes not so easy the first time you cross, pharmacies don't have the stuff you want usually cept like Sos, clen, nolva............stuff it all in a tube sock lay it in the crotch of your pants with a VERY tight pair of like spandex shorts holding everything up good. Go to a gift shop or the market and buy something, or if you are over 21 buy some liquer...then go across, VERY cool like....talk to the customs doods....they will sometimes ask what you are doing how long you stayed and why..tell them you have never been to Mex and wanted to check it out and always buy something dumb to show then at customs.
Done this MANY times...and I know some...well many have been caught but usually its cause they get nervous or something.