One of my favorite sites to check for tips and tricks is Hubspot's Blog. This week they posted a fantastic presentation "Combine SEO, Blogging and Social Media to Optimize Your Marketing Efforts" (embedded below).
As I often say to my clients, try a few different things, see what sticks and then set a schedule. If you are seeing more traffic from Twitter when you post links in the evening, then continue to do that. If you find that podcasts are driving traffic, look at what time of day you saw the spike, the type of content you were pushing out and the referral sites that were responsible for the spike. You will most definitely find a few surprises and the best part about inbound marketing or social media or whatever you choose to call it is that you are marketing "in the moment," you can make changes, perhaps even a few mistakes but it won't hurt your bottom line if you are able to adapt quickly and produce content that is interesting to your audience.
Probably one of the best pieces of advice I have heard in a while is the idea of paying yourself first. In the context of your profession, this means, write a blog post first thing in the morning or do something that will help to push the things you are most passionate about in the beginning of the day. I hear that this sets the tone for the rest of the day and makes your professional life that much more rewarding. I am working on taking this advice starting in January ;).