I totaly agree with eepperly16 comment. One other way to make the proof more concrete is to find one or two examples and work on them simultaneously with the proof.
For example , if you want to prove any theorems on Group theory, you can always illustrate what you actually do working on $\mathbb{Z_7}$ or something less trivial like the dihedral group.
Anyway my point is, use as many examples as possible, so the audience can work the proof on their head with given examples.