If one were to wait for clients before embarking on a shift to litigation, it would be nothing but a monumental waste of time. Litigation is unlike corporate hum drum of fixed silos. One of the best ways to shift from law firms to litigation at 9+ PQE is through Government/panel appointments, which would give a lot of face time before the judges and remarkable opportunities to network. When you start your litigation career, most of the referrals would be from other advocates who do not practice in your chosen field, in exchange for 1/3rd as referral fee. If one were to get appointed as a standing counsel, which is relatively easy, there would be no need at all to wait for clients. The Union/State/Corporation/Municipality/Panchayat would be your client. It will provide enough to meet your expenses. In addition to that, you are entitled to take private disputes, matrimonial disputes, arbitration and general advisory/drafting. After three or so years, you would have built up a solid network and reputation in your area. Things will take off from there.
I have seen advocates who built up their practice from taking legal aid cases en masse during their initial stage. Judges give a lot of leeway and permit mistakes when one argues legal aid cases. It also gives a lot of opportunities in interactions with police and administration. So, for the first couple of years, people do a lot of legal aid cases to learn the ropes of the law and get thorough on all the procedures. You'll also get paid a nominal amount as legal aid fees which will cover the travel and food expenses. In the mean time, efforts can also be made to build up one's personal practice.
These are only a couple of the methods in which a jump to litigation can be strategized. There are soo soo many more. One has to speak to their Senior rather than ask in LI about litigation. I have found LI to be extraordinarily risk averse and dispensing spectacularly bad advice on litigation.

1. Have you saved enough money to last without an acceptable income for more than a year?

2. Are you prepared to spend a couple of years without enough / acceptable case load and without giving in to anxiety?

3. Do you have a network of friends / former colleagues who can refer work or involve you in ongoing matters?

4. Have you attained enough skills and confidence to advise and appear without having to rely on a senior?

If the answer to these questions is Yes, you may consider going independent now. Some oldies will ask you where your office is.. but most clients do not care anymore.