/ Approach Shoe Fit
Should approach shoes fit like trainers (enough room so you don't bang your toes when descending), or like climbing shoes (snug toes for good edging)?
I size mine somewhere in between, but then I generally only wear them if I'm going to be climbing as much as I'm walking: things like alpine II/III ridge scrambles.
That surely depends on the shoe and your intended use of it.
Some approach shoes basically are just trainers with some outdoorsy branding to make us feel special. Probably no point wearing those tight.
Some are really very close to actual climbing shoes, so there might be benefit in fitting them tight but you'll still regret that decision if you're actually planning to walk miles in them.
After a long day in climbing shoes the last thing I want to walk out in is another pair of tight shoes. I just size them like trainers, fine for approaches and descents, and a bit of scrambling. I don't generally climb in approach shoes.
As others have said - are you just approaching in them or climbing in them too?
Only true approach shoes I have used are Ganda Guides. I chose them for comfort, good grip on the foot helped by a highish ankle, abilty to stand on smallish holds ie stiffish, (don't like shoes manufactured with a curved up toe for climbing) and adjusted them for terrain as necessary with different sock combinations, cheap insoles from Boots, and altering lacing. They don't have waterproof lining which is fine for me (lighter, cooler, dry quicker though I take poly bags to put inside just in case). They were brilliant along the Cuillin ridge in the recent dry spell.
Easy climbs/scrambling. I'm not sure I see the point in buying a special shoe solely for approaching climbs, but perhaps given the name I'm missing something!
I've always found them to be slightly narrower than bog standard 'fashion' trainers. Surely if you are wearing them for the walk in AND the climb/scramble you should weigh up how much of each activity you'll be doing.
But generally speaking just buy your normal size.
It depends on a shoe quality which designed for climbing purpose. Search shoes that fit you.
Margo Hayes has redpointed her third 9a+ with an ascent of Papichulo 9a+ at Oliana, Spain. The line was first climbed by Chris Sharma and is a 50 metre endurance-based route.