Sorry, but I couldn't help but laugh. I'd reccoment some pre-made free skins, but custom FREE skins? ROFL.
Me too, Warning: Visiting this site may harm your computer! The website at shadowspace.fi.st contains elements from the site nih-gov.miibeian.gov.cn.craigslist-ca.sugaryhome.ru, which appears to host malware - software that can hurt your computer or otherwise operate without your consent. Just visiting a site that contains malware can infect your computer. For detailed information about the problems with these elements, visit the Google Safe Browsing diagnostic page for nih-gov.miibeian.gov.cn.craigslist-ca.sugaryhome.ru. Learn more about how to protect yourself from harmful software online. I understand that visiting this site may harm my computer.
Good luck finding someone who will do it free. You can try it yourself though, here's a CSS guide I just used last week and it worked out well MyBB 1.4 CSS Guide
You really don't need to know anything about coding. Log into your AdminCP On the left click Themes Find the name of the theme you want to edit. Click on that theme. Click global.css This is where the MyBB 1.4 CSS Guide comes in hand. If you look at the pictures it tell your the name of the different areas you want to edit. Find the name of the areas you want to edit in the "Selector:", it shows a list of names all the different parts of the theme. Find the name and edit it. If you aren't sure what the html color codes are, here's a site that gives you a list HTML Color Names The only way you'll learn is if you try, you'd be shocked at what you can do. If you want setup a second mybb install for trying things like this out. You kill two birds with one stone. You won't have to worry about doing something to you live forum and you are learning mybb's skinning system at the same time.