Using Pipebombs:

1. Pipebombs
You must always remember where you put your pipes. Many demomen have gotten killed by forgetting that. Pipebombs are in general much more effective than normal grenades. However, do not become one of them demomen that always use pipebombs. There are cases when normal grenades will inflict a LOT more damage a lot more effectively. More on that is in the later sections.

2. Weaving
Weaving is a strategy that I use both inside and outside. However, this will only really work if the area where you are fighting is large, such as the space outside the base in 2fort5.

Ok, let me create the scenario for you: Lets say that you are fighting a Soldier. Instead of just firing pipebombs at the Soldier and pulling the trigger when it reaches him (which does work by the way), "weaving" is basically trying to get the Soldier to forget about where the pipebombs are. When you weave, you fire the pipebombs towards the Soldiers feet. If they reach him and you still have time to pull the trigger, then go right ahead. However, if the Soldier is too close, you lead him in a huge circle, and when you get back to the first grouping of pipbombs, you peel off, and when he walks over 'em, pull the trigger. It's hard for me to describe it, but check out the pictures:

Click on image to enlarge

3. Use The Walls
This strategy can, obviously, only be used when there's a wall conveniently available. To use this technique, you have to know your geometry (yeah that's right...math even figures into TF!) But it's ok if you don't know geometry that well...hell I got a D+ my Freshman year! (Well, at least Vorinth did...) Anyway, let me setup a situation for you.

Ok, you're inside the enemy base. You've got your pipebombs ready (I use 'em 99% of the time), and you start heading down the enemy ramps to their basement, when another Demoman starts chasing you! He's too damn close for you to fire a pipebomb right at you, and he's weaving around, so a normal gren might not even hit him. So what do you do? Fire your pipebomb right off the wall nearby. So instead of the pipebomb being far behind the enemy when you detonate it, it's sitting right in his lap when it explodes...ouch!!

Click on image to enlarge

4. Hide yo Pipes fo0
One of the best things about a pipebomb is that you can put them somewhere...and just leave it there. Ok, lets say you just walked into a room, and a big, bad Soldier is standing there with 300000 armour. He, of course, starts to fire and chase you. A great thing that you can do is to retreat to a place where you can conceal your bombs in a place where he won't see 'em 'till it's too late.

Take these pictures as another example of a Soldier coming around the corner:

Click on image to enlarge