Management Consulting: How do you make sure to always show the customer that you create value?

I'll take a step back from the generalities and say I would talk in the language of the business case as much as possible. Express each engagement (or pieces within an engagement) as: 'If you spend $A to do B you will gain $C over X years and/or mitigate risk Y.' Also, I may be taking your question a bit too literally here, but in terms of 'showing' the customer where I (or my firm) creates value, I draw. A lot. As a fellow consultant I am guessing you would have your share of war stories on issues caused by poor communication, misinterpretation, 'chinese whispers' etc. The thing is I don't think words do a good job of conveying the concept of 'value' well. In communicating value beyond words, we could do death by financial modelling, or contract legalese, but I find that the whiteboard works just fine. I sketch stuff like this: Or this: I'm sure you get the idea. When people see a diagram, their frame of reference is the same - this is opposed to speech or text, where the frame of reference is in people's minds (and are invisible, and thus may be different without others' knowing). Now I don't want to minimise the place of relationship in consulting. I think the truth is there are points in time where you get (or keep, or extend) a piece because your credibility and relationship is such that the client might still choose you over a more rational value decision. That is probably a different conversation beyond the scope of this post :) All the best. I wish you well in doing good and worthwhile work.

Focussing on the perceived value, to find out the real reason why you got the assignment, asap after being awarded. The not so obvious reasons that broke the tie between you and your competitors. Expect being lied to on occasion. Sometime deliberately, sometimes because the client doesn't even realise those reasons himself. Than you make those deliverables priority.