This was my first Tunisian Crochet project so I used the following tutorials to help learn the basics and how to colour change properly:
http://www.youtube.com/watch?v=f2MQP0JIi4o
http://www.youtube.com/user/GegeCrochet#p/u/4/WbupvlYzq_U
(Thanks to GegeCrochet also for inspiring the project!)
I made the charts on Excel files, some characters I copied from other patterns found on Ravelry, some from just doing Google image searches and copying from there.
Basically one square is one stitch, the amount of stitches you need on your hook needs to be one more than the amount of squares you need. So in my case, for the big squares I had 65 stitches on the hook, for the small ones, 33.
If you wanted to use different characters, there are plenty to be found on the web by searching for 8-bit Mario or anything along those lines. There are also quite a few knocking about on Ravelry. The only thing was, they were only really picture files which you can’t play with, so I copied them into an Excel file so I could mess with the colours and move things about more easily. For the reverse side of the cushions (big pictures), I supersized the image by turning every one square, into a 2x2 square. I couldn’t add Excel files to Ravelry, so have just put the PDF file up sorry!
To save on stitching (which I’m not great at!), I made the ‘character’ squares two at a time, so crocheted the Princess and Goomba as one piece, with the colour change half way (I hope that makes sense), then did the Mushroom and Lakitu (cloud dude) and stitched the two together.
I couldn’t find guides anywhere on how to sew Tunisian crochet squares together properly, so just used trial and error until the stitches looked reasonably neat and not too holey. I’m sure there is probably a neater way of doing it.
The wool I used was mainly Sirdar DK Bonus, which you can get in loads of colours and is a nice wool to work with. I also used a couple of King Cole Dolly Mix rolls for the skin colour and maroon on the princess’ dress. The size of the covers once finished, are round about standard cushion size I think, but as I was in a rush I picked up cushion inserts from Ikea which I think are a little bit bigger. I just reduced them in size by an inch and a half on the sewing machine. If you don’t want the faff of doing this, a 45 or 46cm cushion pad would probably do the job!

Things I Learned That Would Have Been Helpful From The Start

1) On the basics tutorial video, it says for the last stitch of the forward pass, put the hook through the two end stitches (you’ll see what I mean if you watch the video). Make sure you do this! I didn’t have the internet at home when I made these so was doing it from memory and missed out this step. I had made about 6 small squares and when I tried to sew them together it just didn’t work, as missing this step made the edges pull loads and look really holey.
2) Measure! If you’re using charts you should be alright, but with the first load of squares that I did, I was just guessing the size. Long story short, they were all different sizes and shapes and when combined with the holey edges (above) just didn’t work. I had to pull about 5 hours worth of work apart and start again! So maybe if you are practicing, do a 20x20 square, measure it, and work out whether the size is going to be ok. Mine were always a little taller than wide but this is ok, as you stretch it out when it gets stuffed!
3) On the colour changes, don’t pull the threads too tight. If you do, it makes the stitch narrower, which is ok now and again, but if you’re doing a square with a lot of colour changes, it can make it come out too narrow.
4) On the colour change tutorial, it says to start a new thread if your stitch is more than 4 squares apart. Try to stick to this (though I confess I didn’t always as I got lazy!), or the thread going across the back can bunch the picture up. If you can’t be bothered to start a new thread all the time like me, just make sure you keep the thread going across the back nice and loose, pull it out a bit so it doesn’t squash your picture up.

That’s about all I can think of for now, have fun if you try it!