I decided to trim my own hair tonight & up to now it looks pretty good although I don't want to scrunch it out till morning (it's still airdrying).
What I did was section my hair with duck bill clips so the top layers were out of the way & then started on the bottom layer, I then parted hair in small vertical sections & pulled them at a horizontal angle, lining them up with each other as I went along, I trimmed about an inch all over. Basically how most hairdressers cut it, although I can't say my effort will be quite as even.
I then trimmed around the front by pulling it forwards as I am trying to line up my grown out fringe (just below chin) with the rest of my hair.
The shape definitely looks better already & my curls seem to have bounced back a bit too, they had been getting rather droopy of late.
I will judge the success of this trim better tomorrow or at the weekend when I diffuse.
U.K curly

2C/3A Wavy Whirly & Curly Twirly.
Golden brown with highlights.
Low poo: Dr Organic, L'Oreal Everpure.
Conditioner: Dr Organic Argan Oil, Boots Coconut & Almond.
Leave In: Dr Organic, Boots,.
Gel: JF Frizz Ease, Umberto Gianni.