i have two which work super well.
So one is like when there isnt a set study time, and say if im messaging my gf or something ill say "once i get questions 1 and 2 done ill respond" and that means i get my ass into gear and learn it asap. Then i just repeat this for awhile and seems to work.
Next one is setting a block i want to achieve for eg Q 1-10 in 20mins, then i get to screw around for 10.
Usually i mix the 2 if i have time and just get through chunks pretty quickly.