In the advertising game every creative whiz maintains a 'portfolio' of his work.
For us this would be a wise idea, especially now that pictures can be shared over the internet on the cheap. (MobilMe, etc.)
Before and after snaps, of course...
Other trades display their repair tools: e.g. lathes, mills, welders, portable gen-sets...
For us it would be wise some fine day to photograph your own arsenal of repair. In this respect USED tools look better than brand-new.
Your slogan might be: 'Have skill; can do it.
If high-end detail work is your craft then photograph tight shots of your handiwork.
I find that gee-whiz electronic/ power tools impress even hardened GC's.
If you have a trade-worthy service truck/van it, too, should be in your photo-portfolio.
Other items worth presenting would be licenses, insurance coverage -- etc.
In sum: build a presentation package.
Work up a printed 'standard of quality' for materials... Stuff like minimum wire sizes, THWN-2/THHN/MTW insulation, UL/CSA listed materials, spare EMT runs, if any....
If you are so fortunate include customer plaudits. These should always be framed and posted around client reception areas or cataloged for truck-side presentation.
It is also wise to photograph operations underway so as to show the level of cleanliness sustained around finished spaces.
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So the next time a prospect asks if you are 'certifiable' you can say, "Yes, for the money I don't make, I must be."
