After reading a recent thread, I think some people might appreciate this.
Here's some tips for quick card prototyping:
1. Use excel with a data merge system to make your cards.
I use Cardmaker (https://www.nhmk.com/tools.php)
I print cards even for the first playtest. I do this because a.) I type faster than I can write and b.) It's much faster to make changes later
Using an excel data merge program means you can change multiple cards very quickly and easily.
2. Use the cheapest printer paper you can find and sleeve your cards.
This is MUCH cheaper than label stickers or cardstock. Especially if you have to change anything. Plus if you scrap the game you can just reuse the sleeves.
I buy card decks from goodwill or the dollar store for a dollar to use as backers, but I've also played without backers in the sleeves and it works ok. (I know many people just use MTG commons and lands which you can acquire very cheaply)
3. Make sure your program doesn't leave spaces in between cards on a sheet because that's just extra cuts.
Cardmaker will do a 3x3 grid of poker size cards on 1 sheet of paper with no spaces. This is even easier with a paper cutter, but I don't mind using scissors myself.
Good luck and happy prototyping!
With the program I use (https://www.nhmk.com/tools.php) Cardmaker, it's a pretty simple process.
I type everything in excel, convert to .csv, open cardmaker, and select the reference file.
Then I just create areas on the card and link them to the columns on my csv.