Viable skills / equipment to barter with?

Someone posted about basic tools and repair parts to have extras of, but what about equipment and skills, possibly two separate posts, but lumped into one.

I've also considered other skills I can learn, and equipment i could "rent out" for various phases of economic breakdown, ex: gardening. I have a heavy duty tiller I use, and could rent out or rent out me and it for high value trade if people want to put in a garden quickly. Obviously to invest in this sort of thing means you should probably have use for it normally also.

What other equipment and services are potentially lucrative in trade during a shtf scenario short term and long term?