It's surprising how many have chosen this method to improve their miserable lot.
Personally;I have no experience, (honestly gov) but may I offer this advice.
Don't go for the big one such as 'The Great Train' or 'Matt Brinks'; the police and government will take it personal and pursue you into perpetuity.
Go for the more common smaller heist, or better still, do an inside job. The best type of inside job is information technology or electronically. Banks rarely admit to inside jobs - you might never work again, but you have a good chance of escaping justice with your egotistically earned ill gotten gains.
Unquestionably, without doubt, the best way to rob a bank is to become a banker. Words don't fail me as to how to emphasise the overall superiority of this method over all others.
Any type of banking will get you by in a big way, However; investment banking,in one of its many forms, will hit the jackpot for you.
Whatever you do, do not, I repeat, do not, end up as one of those cloned cohorts of the lower order; the counter clerk.
While you are robbing the the bank adopt a position that will allow politicians, patricians and a surprisingly number of plebs to gently ease their heads up a certain part of your anatomy. This may, at first, appear to be painful in the area of the back pocket but, it has an important two-fold purpose. It will make it a dead cert to evade both taxes and capture. For effect,and to use up my artistic licence swear quota,I'll repeat this in my finest Anglo Saxon.They won't be able to say anything with their heads stuck up your arse.
If, by chance, you are, put before some mild form of public censure - yes the dreaded commons select committee enquiry - you have two possible courses of action.
Pretend you are sorry, - wait a week -resign - wait a week - take up a, different but similar, even more lucrative banking job.
Sail off to your villa where the sun never sets. If by any chance your skin is only as thick as a Westminster wallet,sack one of the crew and keep busy. You will soon forget the old dear killed by the hospital or the disabled person confined to home because they have had their mobility allowance reduced.

Bank robbing is now a national cherished asset.
Robbing an international bank is even more lucrative - rob one and be the power behind the planet - a true, "Master of The Universe".