Common Solo Restrictions:

Day VFR
more than 5 miles visibility
less than 15 knots total wind
less than 5 knot crosswind component
no clouds below 3000 AGL

full fuel for initial takeoff
remain clear of all "B" or "C" airspace

only in aircraft tail number N1111
only between 1000-1600 local time (office hours)

only within the following two weeks
only in radio contact with CFI Mark Boyd



Notes:  I may include all of these for initial
solo, then remove the bottom ones gradually.
The last restriction I remove is the Day VFR.
This is usually right before their checkride,
and they have all the training done, so I've
taught them Special VFR and night flying.
  I think restrictions are important to
track and manage student safety and progress.