My top tip is don't let people see what you have, no leaving your Bike parked out side on view, don't leave garage door open, I have a bolt I pop in a drilled hole so I can have it half open so when at the road side you can not see in and all my bikes are covered the ones near the door are locked to ground anchors and locked together the odd empty box balanced on the covered bike and a sheet of wood leaded up against the bike at the front, just looks like the normal garage junk if any one see's in.
I am very careful with delivery guys as it only takes one in the pub to say, I was at this address and the guy there has a load of classic motorcycles you never know who will ask questions and find out what you have and what they want to nick
there is a down side of looking to well protected as it does show there is something worth going in for, so a mix of in your face stuff and some covert stuff is good.
I am sorry to say you can buy (Or these types can steel) a battery angel grinder for 40 quid that well cut any lock or chain off in a few seconds and with the aid of a pillow don't make a lot of sound doing it, there was stuff on Utube about them doing it
Z1000A1, Z1000ST, KZ1000p, Z1000Mk2 which I am collecting parts for.
Z1R ready for paint, Z900A4 running,
GPZ1100 Unitrack, 3x GPZ 750Turbo,
ZZR1100 Purple and orange
along with some lesser makes