Cut the mana cost of Q. That simple - it would let her actually use in clearing, use it a bit more for wall hopping, etc. As is, it drains her mana pool pretty fast, so you can't use it except as an engage unless you have blue, basically.
I think this would go a long way to making her more competitive in the early game in particular.
I feel the mana cost on it is rather fair, her w and e do just fine with wave clear mid to late game and letting he have a spamable dash and knockup might make her a little strong in lane. where she was designed to be a jungler, where she needs to pick when she uses her Q so she has it for a gank.
Sorry, that's like saying reduce the mana cost of 
's W. They have high mana costs for a reason. After your first clear, if you're building a spirit stone, you'll literally have no mana problems whatsoever with ANY champion. Unless you're using your high cost aoe moves to kill 1 creep. In that case, you deserve to have mana problems.
Sejuani's W was good like after the remake.
Well, primarily I want her clear speed to be slightly better - being able to use Q without draining all your mana would help, but yeah it might be a terror in lane situations.
