it would basically be the same way you negotiate your salary now... just flip the tables.
Currently the employer wants to pay as little as possible, signs you on and continues to pay you $X. the USD is inflationary so the next year while the check says $X your ability to spend says $X(0.97) Im just going to use 3% rate here, feel free to substitute with any other value.
You negotiate toward a raise and the employer negotiates for holding pay steady (read 3% pay cut).
Now flip into a deflationary system. a few options present themselves.
1.) same system reversed - you have salary of $X and want to hold that salary (ready 3% raise) employer wants to cut salary to compensate for deflation $X(0.97). basically base your salary on its buying power not on an amount of currency. take into account changes in cost of living, inflation, etc and you will see what your REAL salary is.
2.) % of revenue - each person would be paid a fluctuating amount that is a direct representation of the revenue of the company. Raises or cuts would probably be int the 10th or 100th of a percent of company/department revenue. I wouldn't expect this to catch on too much but presents an interesting model for sales departments. the better you do the more you (and everyone else) makes. kinda socialist but in small numbers.