Hrm... well, I'll preface by saying I run AD&D, 1.0, so no feats and such to clutter up the sheet. Second, I create sheets in Word, with nothing more complicated than a number of tables to arrange information in.
Top of the first page is a section with basic info - name, class, race, level, hit point, current GP, experience, experience needed for next level, a couple of other things. Generally runs about 1/3 of a page.
Next, an open area for recording damage and healing, and spells which affect being hit. For instance, a character who has 50 hit points, a Stoneskin running, was hit for 10 points and got a Cure Light Wounds for 5 points would look like this, with the first part being the only part saved on the document, the rest temporary (typed on the computer for the DM, handwritten on the player's copy):
50: [stoneskin] -10 +5
Next, what I call the 'combat chart'. This is a list of all the weapons the character commonly uses, with plus to hit (including strength bonuses, dexterity bonuses, magical weapon bonuses, and specialization/weapon of choice bonuses, etc.), then plus on damage (as previous), a note of base damage for Small/Medium creatures and for Large creatures, and rate of attacks, for each weapon. No looking stuff up or calculating, these numbers might change because of a Bless or Oil of Sharpness or some such, but 95% of the time, they are correct.
This is followed by a short section that lists the character's Armor Class, Front/Side/Rear, with the items causing it listed, like this:
AC: F: -2 S: -1 R:2
Full plate, dexterity +1, ring of protection +2
This generally fills the first page. The next few sections are tables for consumeable magic items like potions, scrolls, and arrows; then simple lists of permanent magic items, and a list of non-magic items. At the end of the sheet are the fairly static items like lists of proficiencies, languages, thief abilities, and a character picture if they have one.
Sheets tend to vary from character to character quite a bit, depending on class, powers, and how long they've played the character.
I quite litterally cannot conceive of a pre-created sheet that I could use. I've got all the stuff I need at the beginning, and since it's got (sortable) tables and such, I can easily rearrange things, Find things, and update as I need. Handwritten sheets... urg.