One of the features of OSR games is "quick character creation," and for the most part that's true. Even so, it requires SOME fiddling before a one shot game to wrangle everybody and make a character (especially if you grant random gold and let the players pore over the equipment list--definitely the biggest offender). I wanted to share a technique that's worked fairly well for my one shots. It lets players totally ignorant of the system to slap together a character quickly, and allows for a middle range of character customization. This does require a little GM prep time, but it's not hard if you're familiar with the system you want to run.
I call it the "bifurcated character sheet."
You, as the GM, are going to make a few premade characters for their players. What I do is usually create a few standard flavors of an adventuring party (e.g., Ranger Fighter, Front Line Fighter, Elementalist Wizard, Illusionist Wizard, Cleric, Thief). For one shots, I rarely roll and count gold. Rather, I fill up equipment packs with considerations towards "failed occupation." For example, I make one pack for "Dominatrix" and fill the pack with like, whips and chains, and make another pack for "Outdoorsman" and fill the pack with a tent and a bedroll, and another for "Rat Catcher" and give them a cudgel and a mean dog or whatever. Then, I cut the character sheets of these characters into parts. Separate out the section that details your race and/or class and the one that details your gear.
When the players arrive, I tell them everybody has gets to pick a class (and a race, if applicable) and a failed profession. Go around a circle and give everybody one choice, then reverse the order and give them another. The combinations they make are often really cool and subvert my expectations.
The stupid simple sheet I use for my own homebrewed OSR games is here.