Create MPC order
Go to https://www.makeplayingcards.com/login.aspx and sign in with either Google or Facebook. It is generally not recommended to create an account for Chinese companies, keep your passwords safe by logging in with Facebook or Google.
Go to https://www.makeplayingcards.com/design/custom-blank-card.html, wait for the price list to finish loading.
For the Card Stock Select "(S33) Superior Smooth".
"(S30) Standard Smooth" can be used if you're on an ultra-budget but the quality will suffer accordingly. Sometimes it's noticable sometimes it is not, the recommendation is to stick to (S33) Superior Smooth.
For the Size of deck find the number that's higher than your total number cards. If you want 500 cards then select "Up to 504 cards". Although this shouldn't happen since we got the exact amount of cards in Step 1. Do note that you pay the same amount regardless of any unused cards - so you might as well use them all.
Regarding pricing, you will be getting 1 Deck at the 1-5 Price/deck rate. Whatever price is next to the 1-5 column is what you will be paying + shipping.
For Packaging there are some options available:
Plain White Tuck Box (recommended) - if your order is 216 cards or smaller. For 30c-$1.10 (depends on deck size) you get better shipping protection (against marks and bends) in transit, a super handy storage container and you avoid damaging your new cards when removing the shrink-wrap. The Tuck Box itself comes shrink wrapped.
Shrink-wrapped - If you are on an ultra-budget this is the cheapest option. Although unlikely, you may get unlucky with shipping and recieve bent cards. Also it is very easy to mark and damage your new cards when removing the shrink-wrap (with scissors, knife or similar).
Plain Rigid Box - This is just a Plain White Tuck Box on roids: even better shipping protection, even better storage container. It does cost a hefty $10-$15USD (!!), but if you have a larger order then your only options are this or Shrink-wrapped. It's 100% personal preference but I usually roll the dice and go Shrink-Wrapped for large orders.
The end configuration will look something like this:
Once happy click "start your design".
After the page finishes loading select the blue "Different images" button on the left.
Wait for the page to load again, then on the side click the red button "Upload images".
Go to your first card folder with images and upload the entire folder. Watch some youtube or kill some time while it uploads.
Drag and drop your card images from the right side onto each card location on the left side. Add the desired number of each card, your card list comes in handy here for referencing.
Do this for each folder of images you have. Once you have finished adding all of your images click the blue "Next Step" button.
Skip Step 2 by clicking on the blue "Next Step" button again.
For Step 3 it will depend on what exactly you want on the back of the card. For custom art click the blue "Same Image". For tokens and land cards on the back select the blue "Different Images" again."
Upload just like before then click the blue "Next Step" button.
Skip Step 4 by clicking on the blue "Next Step" button again.
Confirm everything looks good, if there is any issues go back to the page you need by clicking the text under the circle-ticks in the top right.
Click the checkbox at the bottom and then click "Add to Cart".
Confirm all the details of the order are correct and then click "Go to Checkout".
If you don't change anything on this screen you will get an annoying pop-up, dismiss it and continue on.
Fill in the billing information.
When filling in the shipping information go from the bottom upwards, that is, start with Email and continue upwards, completing Country/Region last. Doing it this way will avoid the site needing to re-calculate shipping every time you fill in a field.
Look over the details one last time. Select PayPal (don't enter your Credit Card information on a Chinese site) and click Submit Order.