Compete law and no poach agreement for client servicing and designer employees

Basically we are a pvt ltd company working in area of advertising and animations. Our work involves using diff designing softwares and making innovative videos and animations. Those softwares are usually learnt by the designers themselves..but we then guide designers to actually use those software professionally to bring the best quality outputs required by the clients. in this process they learn various tips and tricks with our exisiting team and production pipeline. They get to know the exact process that how a big video is developed and delivered. also the quality of videos we develop, are not possible to be developed by any other company easily. They either have to learn it from us or have to learn diff things from internet and then form their own pipeline closer to ours. sometimes some of our employees have joined us and then left the company and poached some our other employees as well to do freelance for the clients that we used to work in the company. it not only affects our company future but also the genuine employees asks us to take serious actions towards these kind of employees. Because genuine employees knows that their developed work pipelines are confidential. we just want to avoid that..that people should not do un ethical things after leaving the company. what can we do to safeguard our company and careers of other genuine employees