I use a quite Spontaneous Way!.
1)Do you do any planning for your games at all
No. I look Into Architecture, Wich, now, i have a vast knowledge of any sort of structure; i sometimes just start kicking some segments, and then i start designing,if i want to have a shaded Level, i shade while i add the entities, i never plan anything, i just try to not bore my Mind-Idea and...
JUST DO IT
2)In what form do you design your game levels
I dont use Anything, i use my mind, is an X-80900 Code 100x419 (?) yea, but anyway, no i dont use nothing.
3)What elements do you plan
Well i always Remind what will the player Do inside the place; Like so:
For example:
Do my Character (lets call it Jack, for further Questions)
Jack, Will make a Survival Place for pigmans zombies with face of britney spears (

) Will it be cramped? what would the player choose to survive? barriers?
So yeah; My Designing Globalizes around the Events taking Place.
4)Do you find designing your levels first helpful
No. I already try that, and, at the end, its Horribly Awfully boring, you wont get it done, and you will cancel the game at the end.
4.2 (?) )Comments (Tell me anything about your game designing experience)
I always do tests, and my library is full with custom segs.
I always like to Mature characters, develope them up, ( Jack, from running from Zombie B. Spears pigmans, have come to show his feelings in front of a HQ, since they are discussing how to erradic an infestation of Brad pitt-face Giant rats

)
That's it!.