One warning -- don't buy a loupe if you want to keep thinking your watches are perfect. Here's a phone camera shot of today's watch through my BelOMO achromatic 10x triplet.
I get the 'Buy Aussie' @STANDY and @JimInOz ! My only issue is getting things across the ditch; unless you use a courier packages are sitting at the airport for weeks (have a watch sitting at Sydney International for nearly 4 weeks and can't get it back to courier with FedEx, etc - and a storage box that's been waiting at Brisbane International for 3 weeks...)
An ASCO with headband holder looks like the way to go - 5x is probably enough to do everything?... If I order now, maybe will arrive as a Xmas present!
If you can afford it, nothing is like the Loupe System: https://www.loupesystem.com/ Warring: they are not inexpensive, but are basically the loupe equivalent of a high-end camera lens.
I bought a non-themed Omega loupe on eBay and I am happy with it. When we say "loupe" we're taking about a magnifier you screw into your eye socket, right?