I learnt this spread from a professional that did a reading for me once:
1---2---3---4---5---6---7
8---9--10--11--12--13--14
15-16--17--18--19--20--21
1, 8, 15- self image
2, 9, 16- family*
3, 10, 17- friends*
4, 11, 18- love/intimate relationships*
5, 12, 19- hopes/dreams/wishes/fears
6, 13, 20- near future
7, 14, 21- distant future
*these three can be interchangable, putting the collumn that means most to you/affects you the strongest closest to your self-image, and the least, farthest
I can't remeber her name, but she's the owner of Serenity (a spiritual store in my neighbourhood). I find this reading very helpful in almost any situation, and because three cards are being used in each column, it also looks at things in-depth enough that you're not left second guessing anything (as some spreads sometimes leave me).
I also really like the 3 card spread and the mirror relationship spread. I can't remember where I first learnt the mirror relationship spread...but I've seen many different versions of it since then, so I can't really source anyone for it, sorry. :S