Twitter is the most considered social media platform in my opinion. It's not just about the number of followers you have but the 'quality'. Depending on the client, I compose an event and marketing calendar so followers are kept up to date with business relevant news and events, whilst also incorporating the latest Twitter trends where applicable. View the Twitter pages of my two main clients:
On Instagram, beautiful and interesting pictures speak for themselves! This is such a visual platform and is VERY exciting! For my florist, for example, I do all the photography so I have a large portfolio of images that I can play around with. This is an easy platform on which to gain followers but also to express your creativity and personality. View The Secret Garden Instagram below or click on the image:
Facebook is a necessary presence but a platform on which you need to keep frequency controlled otherwise people switch off. I approach it very differently from both Twitter and Instagram. It is also often where people engage last after they have seen the other Social Media sites and you need to be careful to avoid repetition with very visual businesses.
Pinterest is a good platform to use to promote a particular event or trend. It is obviously only relevant to some businesses, but is good to use for a collection of images.
I update some of my client's Linked In accounts. For Agent Elson, for example, whenever a new music video or commercial is released, I create Linked In posts to promote the work and any associated press they have generated.