First, you are going to need your ingredients; 1. 3 of the exact same bottles (water bottles or 2 Liter pop bottles work best) 2. Scissors 3. Lighter 4. Strong tape 5. Glass (or other material) downstem 6. Glass (or other material) bowl 7. Grommet to hold downstem/bowl in place Now, for the process... Step 1: Cut bottle #1 just above the label (just before it starts to bend upwards) and keep that part Step 2: Cut bottle #2 just before the bottom of the bottle (so it is still a cylinder) and keep the bigger part Step 3: Take the cap off bottle #3 and put the remains of bottle #1 on top of bottle #3 and tape together. Step 4: Poke/burn holes into bottle #1 about in the middle of where it bends upwards Step 5: Take bottle #2 and slide it over both bottle #3 and #1 so it is past the holes in bottle #1 Step 6: Tape bottle #2 on. Step 7: Burn a hole close to the bottom of your new bong (for the bowl) Step 8: Put the grommet in the hole then put your downstem and bowl in. Step 9: Fill the top with water through the top of the bong/bottle (make sure the water level is just over all the holes) Step 10: Fill the bottom threw the hole you burnt for your downstem. Make sure the downstem is under the water level. ENJOY!!! [ame="http://www.youtube.com/watch?v=bw75CsOFO64"]YouTube - Perc Sesh[/ame] This is a video of me and Afro Samuri hitting my home-made perc. I used three 2L pop bottles and made a 100 hole diffusor in the perc.