How about you just spill the beans about your trade secrets
That wouldn't be any fun and wouldn't encourage people to think

Initially I submitted to a load of directories which now aren't worth much juice apparently.
Nothing wrong with links from good directories. Don't believe all you read.
Also have done forum sigs and post links, blog comments and a bit of link exchanges.
Forum sigs good for spidering, and a bit of juice as well. Blog comments, as long as they are on topic and not 'NOFOLLOW' then again they are ok. Link exchanges depnding on how and where they are linked, again not bad (despite what some will tell you).
Must do some article writing soon too. The general thing I try to do is use good anchor text whenever possible. It's an ongoing job anyway!
Article writing, is good if done properly and followed up for maximum affect. Anchor text is the crux here. make it look natural. Don't load all your links with your main phrase, vary it.