A lot of people have trouble drilling glass because it shatters so easily. But there are some ways to prevent shattering. First of all if your going for a bottle, use a bottle with thick glass. Vodka bottles work very well or any other kind of hard alcohol big bottle type thing would work. For drilling, leave a small part of the sticky label on where you want your hole because that will keep the drill bit from slipping around. It's ok to apply pressure if you have a big thick bottle just don't overdo it. I wouldn't suggest drilling all the way through the bottle. Make a small indentation with the drill to get you started then punch out the hole with a small screwdriver then go back to work with your drill and widen the hole as much as you need. Try to make the hole longer vertically so that it looks somewhat like a oval so that you can angle the stem upwards. If you make a mistake, which you probably will your first time, it will not be completely airtight. You can solve this with duct tape and glue but it looks bad. If you want to go to the trouble of drilling another hole for the carb that's great, but otherwise simply connect 2 sections of a pen with a g2 pen grip and pull the grip off when you want to clear the bong. One of the best things about a glass bong is you can color it and make it look trippy As hell when your high. Well those are my tips for drilling glass and making a homemade glass bong!