My goal is to minimize the amount of time I have to spend, with a budget of about $40.
Also, I'm absolutely terrible at using scissors and glue.
Get some card sleeves and card-stock. Write/print whatever you need to on the card-stock and cut it down to size. After you sleeve it they will all be shuffle-able and readable, just like normal cards. Admittedly this isn't good for much beyond prototype testing, but it's definitely fast and cheap. :D
I have two different things I do for prototype cards. The first is just to use scraps of paper and sleeves, as outlined in the answer above (which I upvoted) - it's cheap, easy to swap in cards and stops you from over-investing time into half-baked ideas.
After I have confidence in a design enough to bring it to outside play groups, I usually use stickers on existing cards. Piles of Magic cards are super cheap (commons are essentially free, just ask around gaming groups), and you can use several different labels to print out and stick to them. If you need a couple different backs, you can use different types of dead CCG commons.
Avery makes several different stickers, and there are clones of them that are even cheaper, along with pretty good templates. I've used the White Adhesive Name Badges in the past as the biggest sticker I can fit on a card. They're 2-1/3" by 3-3/8", which is just a bit smaller than a standard poker card (2.5" x 3.5"). Those are great if you have a lot of information. I used to use the 3 1/2" floppy labels for most of my cards, as they had enough room to fit a fair bit of info while being still fairly cheap on a per-label basis, but Avery appears to have discontinued those. I still have a stockpile, but that doesn't help you.
In searching a bit, these look to be the same size as those old labels, so that might work. The nice thing about this method is that it doesn't require any cutting, just sticking, and the cards are very durable and shuffleable, being based on CCG stock.
This week I made a card game prototyper, it converts your google docs or csv to printable cards. http://card-game-prototyper.herokuapp.com/
You can also get playing-card sized sheets for inkjet printers. This is the first one I turned up in a Google search - do some Google work and you can probably find more. Printing on your own printer on these is probably the quickest way to get something that's actually playing card sized. If you can live with off sizes, then go to your local office store and get inkjet printable business cards or 3x5 cards.
Assuming that you already have the following resources:
Then the thing to do is to use a decent software imaging program to create your own cards and backs and fronts. A really good open source software tool is GIMP. Get good at using the image software, particularly understanding layers and work out how to run the same piece of card through your printer so you get fronts and backs to line up (I convert GIMP images to pngs and print from MSPaint, which is good for centering and lining up the images). So far, we have spent 0$ (but have spent some time downloading and learning how to use the software).
You still have 40$ to spend on blank card, either finishing spray or card sleeves and buy a cheap guillotine. The most time you are going to spend on prototyping cards (especially if you have a significant number) is the hours of using scissors cutting out cards (which you say you are no good at) and a guillotine will save you many hours and be much more accurate. You could use a craft knife but the guillotine is faster and more accurate.
A really fast way to prototype card games I found out is to use Excel to create your cards, and then use Word mailing directory function to import data from an excel spreadsheet. Then you just print then out and put inside a card sleeve protector from a random card you don't use anymore.
A good idea too, is to use Google Docs Spreadsheet and edit your card with your friends, then you can download the file as an excel spreadsheet and follow the same steps.
Another tip is to use a 2 columns page layout and create your card using simple tables in directory layout, you will save time, ink and paper this way.
I remembered this question when I finally found my bookmark: http://www.artscow.com/photo-gifts/Card/Multi-purpose-Cards-Rectangle-394 . Artscow will print custom one side (with all the backs being unform) and custom both sides (every card unique). If you google them you can find discussions on art prep and find example sets that others have made public. I think artscow also keeps a database of designs that anyone can have printed.
I'm designing a card game. I made a prototype in 24 hours with $15. I made laid groups of 8 cards out on a normal paper sized image file. I made another image with the backs of the cards. I use Gimp to edit photos , it's free.
To make a set of 100 cards I had to make about 12 pages (24 including back pages) I dropped the image filess off at Staples and asked to be printed on thick card stock and to be cut.
Not perfectly cut but great for friends. Check out an image from it! https://twitter.com/Phasefirefilms/status/210515000840814593/photo/1/large
I know I've already answered but I've found an article on making your own playing cards that you might find useful: http://www.wopc.co.uk/otc/production.html
I'm having trouble finding one that would cut out playing card sized cards but you might be able to find a craft punch that will cut cards to a particular size?
I know you can get passport photo punches that cut out a passport photo sized rectangle from a sheet, you can probably buy one that is business/playing card shaped?
These might be what you are looking for but the bigger one is scalloped which I think means the edges are going to be a bit wibbly the smaller one is quite small.
I've also found a Corner Rounder you can use to round the corners of your cards Which would allow you to use a regular guillotine to cut your cards.
Use cardsleeves which are colored at the back. With those sleeves, you don't even have to very nicely cut your cards, just write it on some piece of paper and put them in the sleeves. From the back side you cannot see the difference between cards.
If needed, you can use different colors.
And what is even better:
- You can even add more notes along with the card (e.g. more clarification; or just a temporary change for playtesting) - You can write on it since they are just some paper. - You can add cards on the fly without the need of printing them BUT without knowing from the backside it is a 'new' card.
Not sure how much of this has been said already, so I thought I'd just go ahead and so it... ^^
For physical prototyping (I use Tabletop Simulator now), I used to go through a number of phases for a quick start:
Resources and (GBP) prices for what I found:
So you can get started for as little as £12, if you wanted to. And have enough for 100. Or spend a little extra and have enough for hundreds!