Problem is, you need to pitch to find a good partner match ...they're also clients.
Sorry, but you'll need to get comfortable pitching ...learn to say what your company does in 30 seconds. Painful or not, practice it out loud in the car every day. Create a video of your pitch and watch it. Create a deck of 10 slides and give a 10 minutes presentation. Practice in your sleep. Use comparisons to other companies and methaphors to hammer the point home.
I find most good matches (whether partners / investors / advisors) are busy & don't have the time (or make the time) to truely learn your business. I have a top level CEO 'advisor' and he's too busy to answer any of my e-mails.
With prospective partners, you need to court them and get to know them over at least a few meetings ...get to know their family situation etc. If he/she has 3 kids under 4 years old, they won't have the time. Look them up in Facebook, LinkedIn, Twitter. Do they have tons of other partnerships? Are they running in a million different directions?
However, when you first meet a prospective partner and they love your business, before any courtship begins, you need to lay down the rules right there and then. You expect the right partner to be highly motivated and highly responsive. All e-mails must be answered point for point. All voice-mails answered. The business must be learned inside and out by a certain deadline. It's all or nothing.
For any partner to agree to all or nothing, you must have a really groundbreaking and lucrative business idea and your pitch must be perfect.