How do I signal touch and touch-in-goal?

Under Law 6.26:

1. When the ball or the ball-carrier has gone into touch or touch-in-goal, hold up the flag.
2. Stand at the place of the throw and point to the team entitled to throw in. (The signals sheet describes this as raising the flag with one arm, moving to the mark of touch, standing there and pointing with the other arm towards the team entitled to throw.)
3. When the ball is thrown in, lower the flag.

You do not lower the flag when:

• The player throwing in steps on the field of play as part of the throwing action.
• The team not entitled to throw in has done so.
• At a quick throw, the ball that went into touch is replaced by another ball, or after it went into touch it was touched by anyone except the ball-carrier who took it into touch or the player who takes the throw.

It is for the referee, not you, to decide whether the ball was thrown in from the correct place.