Drink your coffee from the wrong side of the cup.
See if you can head your rubbish into the bin.
Do your barre exercises at the freezer in the supermarket.
Yes, there are a million silly things not to do, like walking out across thin ice, poking that crocodile, and pushing a custard pie into the face that teacher/boss/policeman (oh, but it'd be fun, though, wouldn't it?) but a little silliness is good for you. It stops your brain from getting in a rut.
I know that someone who's dazed after being knocked over the head is called silly (which I always associate, I don't know how correctly, with the cricketing terms silly mid-on and silly mid-off, which describe people who stand very close to the batsman and are therefore rather likely to get hit), and I'm certainly not recommending getting yourself into danger of any kind.
And I suppose the real cowards amongst us could go in for another sort of silliness, the sort that means humble (as in silly sheep), and this is of course also healthful and charming.
Just do try to step out of your rut today.
People will love you for it.
As long as you're careful.
Thing To Do Carefully Today: be silly. This word meant pitiable in the 1400s. It comes from the Old English sǣlig, which means happy, and is related to the Gothic sēls, which means good.