Drill to teach avoiding offside.

4 or more players
pylons
lots of balls

Drill:
Player #1 passes to player #5.

#1 Runs to the line of defenders (pylons) stays on side while running towards the ball.

The moment #5 passes player #1 cuts to the goal.

Player #1 scores.

Rotation:
Change lines.

Variations:
Remove or add a goalie.
Use moving real life defenders.