Starting your own firm? Private planners only make up 20% of us professionals, I believe I saw somewhere on the APA website or on some form of planner propaganda. Given that the majority of planning seminars and surveys speak in this way, it's a wonder anyone works private. Also makes me wonder who is representing developers out there??? I strongly dislike repeating myself, but I can't help but to check the "other" box on a survey when an answer more suitably fits those of whom work in government, and I have no choice but to remind them that private planners are people, too.
I work a lot at not freaking out about having work- or not; that my client is just not getting that exactions are the norm and quintupling your density isn't a right, it's a privilege; or how politics are infused into what we do- regardless of any code. It sometimes isn't easy, and I have to remind myself that I love what I do in these moments. I also remember that I have been doing this for some time now, and I know my stuff.
But it ain't easy. I strongly recommend that you learn marketing, take a public speaking class, attend conferences, network and drop business cards where you can. But the biggest thing you have to do is to not take things personally, and be prepared to walk away. Life is too short to pull your hair out over not having enough affordable housing in your application, or if the planning commission demands all buildings need to be chartreuse. Pick your battles, learn to meditate and love the freedom the private realm offers: loads of vacation time, flexible hours, and choice of projects. Believe in your skillset and your training, and don't stop learning. Choose your words, and keep the faith that you are an important part of your community and a vehicle for change. It's often a behind the scenes fight, but when you look out and see people jumping up and down because their project gets entitlement, you are an unsung hero and an important cog in the machine. Plan-nerds unite!