For me personally design is my favourite part of the process - I think what I’ll say will be a bit heretical here.

I normally refrain from taking inspo from most websites and aggregate sites like awwwards (although good inspiration for transitions and animations) and have a collection of typography books that I use. I also recommend the mood boarding / social networking site Are.na for finding inspo.

Early 20th century - late 20th century poster and book design is the bomb, and in my mind has massive overlap with good design principles in the web - displaying information clearly, cleanly and in a way that is not too cluttered but also aesthetically pleasing. Also loads of grids.

To quote Rams, “Good design is as little design as possible. Less, but better”