Thought I'd post a few pictures for comparison. With some of the bulbs I recently obtained, I took one or two scales if I thought the bulb was sufficiently large enough (i.e. out of 3 'Pearl Jennifer' bulbs I took 5 scales). Half the idea was to get some practice/experience with scaling rather than clone any specific cultivar.
I soaked the scales in a dilute bleach solution for anywhere from 10-30 minutes (depending on whether I forgot them or not), allowed them to air dry for an hour or two, then placed into a ziplock bag with some sphagnum moss. The bags were then wrapped in a spare towel and stored in the wardrobe. I don't think this was a good spot for them initially, since nothing happened for weeks and so on the 7th of July (19 days ago) I moved them into the hall cupboard (at the time, no bulblets were visible). I was rather excited to find the first few last weekend and surprised at how quickly they've grown since then.
"Pearl Jennifer"
5 scales (started incubation on 11th June / 41 days ago)
3 scales have produced 4 bulblets so far (leftmost has a really tiny one that doesn't show up in the photo)
"Tiger Babies"
3+ scales (not sure; didn't record how many; started incubation on 26th June / 26 days ago)
2 scales have produced 4 bulblets so far; interestingly, these also have a lot of roots
The others I have incubating haven't got any bulblets yet. I've only had two scales go mouldy (Mapira) and realised that the issue was that the scales were pressed up against the side of the bag and the edge was collecting too much moisture.
My plan is to let these particular two sets of bulblets grow a bit more and then put them into the fridge for 8 weeks in early August (probably in about a fortnight's time). That means they should be ready to pot up in early/mid-October, so hopefully they won't be much out-of-sync with the season. The others, should they produce any bulblets, will probably just be a month behind.