Take the remaining four tees and attach them to the 3" nipples. Now you'll screw the four 24" pipes into the bottom openings of the tees, pointing down to the floor, and screw the four 4" nipples into the top openings that will create the supports for the table top. You'll want to hand-tighten the connections as best you can while also aligning the pipes in a way that they'll create a stable stand.
At this point you can spray paint the base with any lacquer paint, we went with a gold gloss to offer a nice contrast to the industrial style of the plumbing pipes.
To create the vanity top, we chose inexpensive S4S (surfaced-four-sides) pine lumber, cut it in half and laminated two edges together with wood glue to create a 5' long by 14" deep surface. When choosing your lumber make sure to look for a piece that's relatively knot free and straight with no warping or cupping. Apply glue to one edge of each piece and clamp together. Once dry, you may want to do a little sanding to smooth out the top, then leave natural, paint, or add a couple coats of poly.
The final step is attaching the vanity top to the base by driving four screw up through each of the top most flanges. Now all you need to do is add a mirror on the wall and the perfect little seat and you've got a custom, self-built vanity!