I think I post every year about some of the *potential* tech issues/obstacles - this is based on who I've worked for in the internet industry (and I work in Security, not web design).
SeeTickets will use a number of tech solutions to prevent 'attacks'. Basically mechanisms designed to prevent the site crashing (though they've failed many a time on that!). They need to find ways to allow proper buyers who are F5'ing like mad, but not letting bots or automated apps overload their servers.
If everybody used Refreshinator, there's barely a site on the planet that could cope with a million people doing that level of refreshing. Even if it's built with the best resilience. So my advice would be, don't use it. I can't confirm that they WON'T block your IP address (if they use a DDoS protection product or Web Application Firewall (very likely), which will be a third party app, it might judge it to be attack traffic and block). You do need to be mindful of that. It's not about how many times you can refresh in a given minute etc. I think it's already been mentioned on here that around 60 refreshes a minute has the potential to prevent you progressing).
VPNs won't get you any more joy than normal, other than if you have a number of you in your household trying, it's not the worst idea to split the traffic up across IP address ranges by using VPNs.
Annoyingly, See Tickets still don't seem to fully separate their booking flow from the main landing page servers. So even getting to payment pages can result in crashes. If the page hangs or you get an error message DON'T REFRESH. Click back and try and click through again. You'll have a cached page and won't get chucked back to the start. If you don't think payment has been taken, try the same thing - it should know that a purchase has or hasn't taken place.
One year, See made a screw up and had all their traffic going via one server, not load balanced across two. Which meant you could manually alter your settings and get onto the second one which had almost nobody on it. They're unlikely to make that mistake again! Setting yourself up to only point at one server this year will actually half your chances, not increase them.
There really aren't many tricks. Refresh at a steady rate, get your friends to try to increase chances, pool up with others, then just pray like f**k, if praying is your thing. While See's tech is still not quite Netflix, they've got a lot better and if 'cheating' were possible, trust me, we techies would be all over it and not posting it here, haha!