I have been consulting for over four years now. I have worked with over 20 clients. The range is wide. I have worked for Fortune 100 companies; literary agencies; major publishers; independent publishers; tech start-ups and industry organizations. I generally try to work with 4-5 clients at a time.
One of the major keys to being a successful consultant is to have enough clients to maintain the business.
It is important to “keep the pipeline” full at all times. Any lull in being at full capacity is a hit in the cash flow. Because as an independent contractor, I only get paid when I work. There are no days off and no paid holidays. Every day not working is a day of not earning.
How to keep the pipeline flowing? I like to classify accounts into the following buckets.
1) Active – these are the ones in play today. Some are accounts that are short-term, others long-term.
a) Retainer-based : Advising on a regular basis. Generally done in 3-month trial and then renewed each month. This is an “always-on-call” relationship and not based on any specific project although there are numerous initiatives. 
b) Project-based : A specific task or report. Many of these are a market analysis. There is a definite deliverable and time-frame. Generally these projects can take 2-4 months. Many times a project does evolve into a retainer. Especially helping with the execution of the suggestions.
2) Sleeping – companies that have expressed interest and there is a distinct possibility that an agreement will work out.
a) Morning – A decision has been made to work or not.
b) REM Deep Sleep – Have had a few discussions with the potential client, but there is still a lot of consideration.
c) Early Sleep – Just had an initial meeting. Just starting to figure out the potential (from both sides).
3) Dead – either an account that has ended and is done or a potential one that is not going to happen.
a) 6 Feet Under – Projects end and there is no more work. It is over. Always end on a positive note, but best to move on.
b) Dead can go both ways. It can remain dead or can have a second life or even a third one.
c) Coming back from the dead is a Zombie.
4) Zombie – return from the dead. Some clients return.
a) It can be a few months when a client needs a bit more work done.
b) It can be a year. Many times a project ends and there is no more work until the next budget period.
c) It can be years. Unless the situation was a disaster (and thankfully every client has ended on a positive note), there is always the possibility.
I have been fortunate and have enjoyed working for every client. When I refer to Zombie, it isn’t in the negative. It is a term of endearment for some things long buried can be current quickly.
The key is to always add value and know when it is time to go and time to stay.
