Dives 6-9 after cert. were solo for me...intentionally. I dove doubles on my first OW dive, and changed them to independent doubles on my third (and all following) dive..the rest of my gear followed suit quickly.
I was plenty comfortable with my initial solo dives, even though it was a new area (fresh water lake). Vis was great, water was comfortable (31-38degrees..lol), potential for entanglement was very minimal (which makes my stomach knot thinking about..lol..but have dealt with now). I felt very at ease, practiced (and still do) switching regs, buoyancy, different kicks..etc..As well, it is an amazing feeling of being alone in a brand new world. I do stay in the NDL, but sometimes drop down to the 70' mark or so for a few minutes....depending where I am..
Some of the places I have solo'd now, I can probably say that no other human has been to, or seen ever...pretty neat experience! I love my freshwater solos.
I have yet to solo in the ocean as I have a great group of buddies when I go there...in time though, I am sure I will.