Nothing new, but personal fave is offering to pay for meals in groups and taking everyone's cash.
De-cluttering by selling old crap works well also, you can even earn brownie points from the wife doing this
When your phone is due a new contract the old one will probably pay for a punt.
If you earn a bonus at work, don't tell the wife and get it paid into a different a/c.
One only a few people can do depending on their position at work is get petty cash for the business.
Another slightly expensive one is get an online credit card with no paper statements. Then get cash out on it. Helps if you have a lot of work expenses to mask personal expenditure.