Easy SharePoint custom form
One of my colleges sent me this link which I find it very useful for all SharePoint versions and environment. Yes, it is working for Office 365 too. All you need is a little bit of JavaScript skills and concept, then you can implement it. The best part is that you likely won't have to do any update to the script and it'll just work. I know I'm going to refer to it later. And here is the link. http://www.markrackley.net/2013/08/29/easy-custom-layouts-for-default-sharepoint-forms/