This is super important because as a consultant you're juggling many things. You're essentially a small business of 1 so you need to know how to structure your time and how to work even when you don't want to. I've met many consultants from many industries and have found that one of the most important things they all mention is that you need to be able to just plan when you're going to work and commit to that work. If you cannot work without someone looking over your shoulder or checking in on you then you're going to really struggle to meet deadlines.
Setting expectations with clients is super important as those clients are going to want those expectations met and you as the SEO consultant are going to want those expectations to be exceedable as this sets you up for stellar reviews and a raging fan base of clients and ex-clients always willing to send work your way.
Having tough conversations with clients is going to happen sooner or later. I rate this a 3 in importance only because if you're skilled and dedicated it shouldnt happen too often. It is important though that you can take criticism or give it when it comes to working as a consultant. There should be an air of honesty between you and your clients when you're consulting because you want to make sure you do the job well in a manner they are happy with and, that you can give them honest advice to stop them from pursuing strategies or paths that may hurt them in the long run. Such as, if a client was to say that they want to engage in some kind of spammy or blackhat link building tactic.
This one goes without saying really. You want to deliver on time or before to keep people happy. That means you can schedule your time correctly and finish things in the time you have allotted yourself. To allot too little time will lead to stress and burn out. Too much time and you're going to procrastinate on the work and then only pick it up when its urgent. Again, leading to stress and burn out. When you're the business, which you are as an SEO Consultant, you can't afford to be off your game for too long or to be always stressed and burnt out. You need to manage your self care.