There's always e-mail follow ups. It is important to provide new and relevant sales information for the client everytime you email them. This is the time to focus on specific points about the product and service that you are offering. Just a word of caution: Don't SPAM. Even if it's not, make sure your email does not look like one. Make it as personal as possible (I will write a hub on this)
Texting or SMS is another way to update your prospects. However, make your text relevant to the potential client. But make sure you keep it simple and direct. Most people read their text messages so this is a great sales strategy.
Office and home visits can also be done depending on the situation. What it is important is to make an appointment first. Make your visit short. You can simply drop additional brochures, pamphlets or other paraphernalia and that's it.
If your company is offering freebies, discount cards and the like you can give it to them.
The two most important things your prospect must remember is your contact details and product/service your are offering. Don't Try to close the sale when following up on clients. That's a common mistake that will make your prospects hide from you.
Follow ups are reminders for clients that you and the products/service exists. If clients don't know you exist, they won't even start looking for you.
These are just some follow up activities you can do. Hope this helps. Good luck and happy selling