Without Xactimate, format everything in detail one line item per service, give them (adjusters) all the line items; the line item, its unit price, and its respective qty then a subtotal.
Include a dimensioned sketch noting affected areas / materials
Keep a drying log from day 1 through to dry
Keep 1'x1' trim, carpet/flooring/pad samples if anything is torn out
Other than that it's just dressing that info up on an invoice
That's the bare minimum - if you want to go further;
Test your dehu/s rH drop daily and log it - adjusters will sometimes want justication of why something took 5 or 6 days to dry, even with logs, you can get the "must be your equipment, i'm only paying for...." If you measure your dehu's drop daily, you can show them your gear was working as it should, sorry, pay my bill.
Make sure you have a well written work auth, we are finding - for whatever reason - more and more adjusters asking for it.
If you want to PM me your e-mail, I'll shoot over a few Xactimate pdf files.
Where you are missing the boat by not using Xactimate;
Base service costs, recouping materials sales taxes, O&P (which is a free 20% of gross of the entire job handed back to you where there are more than 3 trades happening), figuring out "better" line item selections, for example, if you took out 2' up from bottom of drywall on 100' LF of wall, (200sq ft) instead of charging 200x0.73 or $146, you know to use the up to 2' per LF line item @ 2.43 which fetches $243, charging for things like PPE, equipment decontam, knowing you can charge $350 to fix 1 square foot of drywall, then $170 to paint that 1 square foot, (minimums) and 1001 other ways to wring $$$ out of every job.
You can always get by with the 2000 pages of line items Xactimate has - but you can do a $30k invoice in 20 minutes with Xactimate and probably not have a single one of the line items ever questioned. If you do more than 15 a year, it's worth the $135/mo. You'll make it back x2 not counting your time saved.
And if you ever get to a point where you are doing more water losses - you are one huge step ahead of the curve to keep growing it.