How would I make a logo in Touch Embroidery?
At present, you likely would not. You'd send away to a digitizing service for a logo. There's a large number of companies with the expensive software tools that specifically cater to this sort of work (E.g. Quality Punch) . They are fast and professional and know the ins-and-outs of embroidery and machines to sew them on etc. There's a lot to getting things a good logo. My work tends to veer a bit away from this and more towards the home embroidery user and more artistic work.
While I am working on getting more vector-like fills and reinventing the wheel with regard to some of the math that got set in place a long time ago, seemingly wrongly. It's not there yet, but even when the rest of these tools are properly established there would still be considerable know-how required with regard to sewing out a good set of embroidered shirts, or the like.
If this is your goal, I'd recommend just using a service. If your use is more general there's a lot of already made embroidery on sale for a couple bucks in a variety.