Writing your newsletter
If you write a newsletter, be it weekly, monthly or whatever, try to write in blocks. It can be hard to find a quiet time to sit and write, but, when you do, you often feel like you could write for hours. Do it whenever you feel inspired, and then split the content over several newsletters.
Writing your blog
The same advice applies when writing blogs. However, the advantage with blogs is that you can schedule your posts in advance. I am actually writing this on 30th October but you will be reading it weeks later!
If you have a profile on sites such as Ecademy and LinkedIn, it is easy to spend hours each day responding to requests to link. Set aside some time each week for social networking and respond to invitations then. Also, use this time to seek out new connections of your own, join and post to groups, etc.