I’ve been using OmniFocus for awhile but I sometimes do struggle with finding projects for tasks. Especially lately. What I’ve been finding helps me has been using a couple of custom perspectives that Sparky suggests (I’ve attached iOS screen shots later).
I use the “clear” perspective to see all tasks I have available to me, even if they are single tasks still in my inbox. At the start of my day I pick a few tasks that I want to tackle that day and I flag them.
I then switch to the “hot list” where the flagged entries and the due soon tasks show up. I love using due dates since they’re a hard deadline and OmniFocus will auto add them to the hot list when time is running out on them.
I agree with you that hyper scheduling is appealing. I have a number of items in my day that I think of as boulders - these are events I have no control as to postponing and I must attend (I’m back to being a student - so lectures are my boulders). I know the rest of my day must flow around the boulders - so I schedule time that is “work time” around these boulders. If I’ve prepped my day properly (either the morning of or evening prior) my OmniFocus “hot list” tells me what I have to do. If I get through that list then I always have the luxury of going back to the clear list to find other tasks to work on if I still have time. On the flip side - I’m toying with using an “in progress” tag for tasks I have started but not yet finished in my working time slots (a separate perspective for these can mean I start a work session with “in progress” move to “hot list” then end with “clear”).
GTD is a great starting place and perfect for removing tasks from your mind. But I think we all have to adapt our task management to what suits the way our mind works. I don’t like reviews and I like the shortest pre-planning possible so the above works for me. I find I can be lazy - so I try to work with a lazy mind to be more productive and also have OmniFocus do the work of telling me what I have to do.