Looking for level design advice

[Daydreamer_93]

Hi there

I'm looking for some advice on how I can teach the player through level design. I'm working on a puzzle platformer and have to introduce the player to a clone mechanic. When the player can't progress any further they can either end their life and restart with a clone that plays through the last life or they will restart when the timer runs out. 

I'm trying to figure out how to teach the player that they can stack on top of clones to reach a higher area. All I can currently think of is putting a wall/enclosing them in at the beginning of the level to force them to figure it out.

I was wondering if anyone had any other ideas?

I'm also looking to introduce a kick mechanic that kicks boxes out of the way either by the player doing this or they can use the clone to kick them across an open gap or something.

Appreciate any help/feedback at all