My advice... FedEx everything.
In my bachelor days, I used to pretty much live on the road as a field service technician. Pre 9/11, I used to check my tools, PPE, and test equipment. Eventually, as security tightened, I found it was much easier and more reliable to FedEx everything (excluding my carry-on computer bag and a small suitcase containing clothing and basic PPE). These days, for domestic flights, I wouldn't think of carrying on or checking anything tool or test equipment related.
FedEx Priority overnight is an amazing thing. A while back I had a job to do up in Alaska, followed by a job in Chicago. I finished my job in Alaska, drove to the FedEx place in Fairbanks and dropped off my tools/test equipment to be shipped priority overnight to the jobsite in Chicago. From there, I went directly to the Fairbanks airport and caught the next available flight to Chicago. When I arrived in Chicago, I hopped in the rental car and made my way directly to the job site. My FedEx stuff were already there! I have no idea how it beat me there, but it did. When I finished my Chicago job, I FedEx'd everything back to my office before catching my flight home. Magically, everything was at my desk when I got back to the office. Somehow, FedEx packages ALWAYS beat me to my destination.
I don't miss schlepping a bunch of heavy stuff through airports, and at this point, I trust FedEx more than I trust the baggage handlers to get my stuff where it needs to go. Fortunately for me, my employer pays for all of the expensive NDA shipping. I might rethink my strategy if I was paying out of pocket.
International travel is different. I put a lot more planning into what i take, and only fly with the bare necessity tools, test equipment, and PPE. I only seem to run into problems with the US TSA. The rest of the world seems much more reasonable with respect to getting my stuff from point A to point B via airplane.
In closing, here's a stupid joke I heard somewhere...
Q: Do you know why they don't let old ladies on airplanes with knitting needles?
A: They're afraid they'll knit an Afghan.