It is a bit of a harsh jump, but if you don't have anything else available, just make up for it with the extra strokes on the leather. Get 3000-4000 when you can.
You can get a super edge with the tools that you've got already, but the 3000-4000 will save you quite some time.
I go from 400 (chips n' stuff) to 1000 (minor imperfections) to 3000 (honing begins, knife becomes shaving sharp at 3000) to 8000
to 12000 (12000 is kind of overkill, but what do I know?! I do it anyway) on my waterstones.
Of course it depends on the condition of the edge. I'd say that you could go from 1200 to 4000 to 8000, or 1200 to 3000 or 4000 to a leather strop.
The difference between 6000 or 8000 is not so huge, as you could easily get the same results with both. It's all about the technique and how much pressure you apply when doing the final honing.
Actually, I sometimes go over to the strop after having honed at 8000 or even 12000 on my waterstonse, because
they can leave scratches on the blade (no matter how well I clean the stones!) and the strop polishes those away nicely.
I mean, as long as I can shave hair and push-cut newspaper with my blades then I'm happy.
I don't know of any other method to test the next level of sharpness, but I'm sure someone will come along to enlighten me (please do!).
