I’m working on things where there is no VS and no fancy things, I have SPD 2013 (by the way IMHO sucks big time) and using Jquery, SPService and Javascript to get the things done.
I should say so far I had success with Jquery, SPServices and Javascript but there are few things that will need atleast 100 lines of code to get things done but using CSOM its only just a line.. ya a line can you believe it, initially took time to dive in but after that its a smooth road, I should admit MS did great job with CSOM and REST.
JavaScript API (http://msdn.microsoft.com/en-us/library/jj193034.aspx)
In coming days will start posting my code samples which include how to get User Profile Image from UPS and place it on any IMG tag.
How to get ID in newform.aspx (but i am still struggling to pass that ID to editform and Dispform in query string.. I know there are couple but none is working in SharePoint 2013).