Additional Custom Fields In Registration

Hi there,

So far I already made my custom made registration page but it only contains the required username and email address. My question now is how can I add additional fields into my registration page? I don’t want to use any plugins as I will turnover the site to my client who’s not familiar with wordpress and doesn’t want to do the techy stuffs.

Can someone help me? I already googled it but somehow i can’t find one that actually works.

Thanks in advance.