Pieter,
There are basically two strategies for using modern rapid fixers. Ilford promotes the use of a stronger dilution of fixer, shorter fixing times, and, subsequently, shorter wash times.
The more "traditional" approach is to use the fixer in the weaker "print-strength" dilution, fix for longer and wash longer.
Note that if you use RC papers, the issue is largely moot - just use a stronger dilution, fix lots of prints (follow the manufacturers' capacity recommendations) and be done with it.
The real questions arise when using fiber-base paper.
When fiber-base paper is fixed, fixer, along with all the fixing by-products created during fixation, soak into the paper base. These can be hard to wash out. The two strategies above are two different ways to deal with this, along with the use of two-bath fixation and the use of a wash-aid (Kodak Hypo Clearing Agent, Ilford Wash Aid or similar).
The Ilford Archival Sequence is described here:
https://www.ilfordphoto.com/ilford-optimum-permanance-wash-sequence-fb-papers/
Basically, you fix for a shorter time (1 min.) run fewer prints through your fixer (10 8x10s per liter with one-bath fixation) and get to wash for a shorter time. The advantages are that the process is fast and saves water.
The more traditional approach is to use the weaker dilution of fix (1+9 for Ilford products 1+7 for Kodak Rapid Fixer), use two fixing baths, fix for longer and wash for longer. The advantages here are that it is more economical and you don't have to worry about overshooting the 60-second limit on fixing time.
Personally, I prefer the latter method. I fix for 1.5 - 2 minutes in the "print-strength" fixer, rinse for five minutes, use a wash aid and then wash for 60 minutes.
Hope this helps,
Doremus