Simply, put your unique stories on Digg and make it an interesting one through the compelling title and tags and writing a good piece of description..!! Digg other people's stories and in response they will Digg yours..!!
Always shar in public your pages. Same with Diigo, you need to set always in public your links that you share.
Publicly bookmark your different urls on these sites. Because these sites have a huge amount of visitors so you'll get benefit of it.