Make a subclass of one of the HUD classes (or anything with a postrender function in it).
This class must have a post render function in it ,that is were you'll make all your drawings.(If you're making a hud for a tournament gametype you'd want to make it a subclass of challengeHUD or ChallengeTeamHUD if it's a team game).
Noow to actually draw things on screen you have to know the secrets of the canvas class.The canvas is a reference to the displayed screen on the player's machine ,here are the main functions and variables:
canvas.setpos(x,y) go to pixel x,y
canvas,drawtext(String text,boolean carriageReturn)
canvas.drawIcon(texture,scale)
canvas.drawTile(texture,posx,poy,endx,endy,scale
canvas.clipx
canvas.clipy these give you the resolution of the screen on the player's comp
canvas.drawcolor change it to the color you'll want to use for the next drawing operation
there are several others check the canvas class as well as the EPIC Hud classes.