To accept criticism, make a critical, even the word is aggressive from the start. Topping the list of types of criticism there is the "constructive criticism"! What an aberration, how a critical can be constructive? By definition a critical is a blame, simple as that.
It is so easy to criticize people acting, criticizing design, organization, how people are dressed, how people go about doing things. I want to point out that whatever the criticism, the receiving it is instantly negatively affected. It's not possible to build something if you start by blaming.
If your intention is really to respond positively, I suggest you never criticize, but simply ask questions to understand the process used and then re-explain the purpose and outcomes and then work on amendments from suggestions and similar example you may submit to clearly present your point.
I do not mean that you are wrong to criticize, I understand that in many cases it's legitimate and necessary. However, if you want to increase your chances of being carefully listened and you sincerely want to help people, it is important not to confront people if you want these people to listen.
Think about the way in which you can explain your views, your guidance without starting with a review. I secured from the outset it will be easier for you to deal with situations since you have a REAL constructive approach.