Yes, doing the work and selling the work and getting paid are 3 different jobs.
It is possible to build a sustainable business on top of 90 day engagements. I don’t recommend it, but it is possible.
You need to consider yourself a small business. Not a freelancer, not a consultant, but a small business.
Get a good accountant to keep you um…accountable.
Alan Weiss is my favorite author on how to run a high margin solo business.
The "value based pricing" book was great. Here's a nice "hot take": https://www.alanweiss.com/styles/pdf/The%20Case%20for%20Valu...
re: sustainable business on short engagements - I had a mix of long-term contracts and short-term gigs. The short term gigs were the most fun, but most stressful, so I always tried to bill them at the highest rate (and didn't mind if I didn't get the gig because I was bidding too high). I valued the long-term gigs tremendously for the "stability" they provided.
Having a diversity of Customers was the key to my piece-of-mind. As long as I didn't do something so bad that my name would appear in the newspaper I knew I could screw-up with one or more Customers and still have a livelihood, even if I did have to tighten the belt for awhile.
I can't agree w/ the statement re: considering yourself a small business enough.
Definitely have an accountant. Learn bookkeeping if you want to minimize accountant expense. Take a 100-level college accounting class and you'll know enough for a solo venture.
* Value-Based Fees
* Million Dollar Consulting Proposals
Any one of those will have bits of the other two in it. MDC establishes the mindset, the other two are deep dives into setting fees & drafting proposals the learnings in both of which served me very well.