The easiest way to be giddy is to whirl around in a circle a few times, but I'm not sure I'd recommend this to anyone over the age of...oooh, about seven.
If you're seventeen then you probably need a roller-coaster.
If you're seventy, then just getting up quickly may do the trick. Or even forgetting that you're wearing your varifocals.
The other sort of giddiness is much more fun, though. It means to be scatterbrained or impulsive.
Now, scatterbrained is Homo sapiens' natural state of mind (let's all stop for a moment to laugh at that sapiens, shall we? Because it means wise); and impulsiveness is full of delights.
What a lovely day to skip down the aisle of a supermarket.
What a lovely day to see how many people you can persuade to join you in a conga.
What a lovely day to...
...but this is no good. If I suggest something, then by definition I'm stopping you being giddy.
Anyway, I'm off to see if I can kick some leaves back up onto the trees.
Thing To Do Today: be giddy. This brilliant word is from the Old English gydig, meaning mad, or frenzied, or possessed by God.