SEM strategy

Wow, the week just flew by and I didnt even get a chance to write a new post....things have been a bit hectic at work, but still, no excuse!
I've reached the point in my career where I've acquired enough knowledge about search engine marketing and online marketing to do most of my daily tasks almost instinctively, but there is a skill I still need to master....planning!
Working on many different online projects in 3 languages is great but it's very easy to forget some things or miss out a key element, hence the need for a clean SEM strategy.
The question is, how to organise it? The way I see it, any work I do on my company's websites is linked to SEO such as netlinking, adding new content, updating news. But SEO has become such a generic word that a strategy needs to be much more granular than this. There are so many things that need to be included that I'm always worried Im going to forget something, so if anybody has a definitive list of what an SEM/online marketing strategy should include, please send it to me!
I'll work on my strategy next week and post it here to get some feedback