There are many ways to put your robot together. I mean MANY. However, there are a few very common methods that show up on all the robots, if you look hard enough. AND HERE THEY ARE!
Welding
Welding is one of the more permament methods of putting things together. Unless a LOT of force is pulling it apart, it won't even budge. HOWEVER, welding can only be used with a welding machine, which can be a bit more than some teams can afford, and it can only be used on steel and aluminum. Also, there is the permament part. Once something is welded shut, it can't be pried apart, making small adjustments to it impossible. Be sure that, before you weld, you have figured out EXACTLY where everything goes.
Rivits
Riviting is not quite as strong as welding is, nor is it as permament. That is both good and bad. It is possible to take apart rivits, although you ruin the rivit itself. This is a good alternative to welding for teams that don't want to buy the welder.
Nuts & Bolts
Bolts are not permament. They are very strong however, assuming the other robot doesn't carry a nut-driver. Bolts are often used to secure some of the more detailed parts of the robot, the ones that aren't going to move around much and might need to be taken off for minor adjustments. Thanks to Extrusions, essentially Legos for robots, bolts can be used to hold an entire robot together. I would definitely suggust that, if you have enough money, use extrusions and bolts to build your robot. The biggest danger is the shaking and bumping that occurs in competitions that has a tendency to loosen them up.
Zip Ties
Zip ties are extremely useful, and can be counted on to hold under minimal force. This should NOT be used extensively throughout your robot, as it has a tendency to break if pulled on hard enough. They should be used mostly for quick fixes between matches.
Game Time
That's right, you get to be subjected to another of my creations. This one is entirely text, so there are no pretty pictures. Tiss a shame, but I didn't know how to make a picture of a screw in photoshop...
