Teacher assistants play a vital role in delivering instruction to pupils. I have seen them called by different names: teacher aide, in-class support, and education support professional. I think that the latter is more fitting and appropriate because their role is just as important as the teachers' to ensure a smooth process in instructional delivery and supporting the student or students’ unique needs. Here are four ways to achieve that successfully:
1. Know your role and play your role as a teacher assistant.
What type of assistant are you? Are you working one-on-one with a particular student? Are you working with a group of classified students? A clearly defined role will help in setting a foundation for success as some of the requirements may differ accordingly. This knowledge will prioritize your supervision whether it is the safety, health, social, and or emotional learning or helping the student to assimilate the curricular content. Depending 
on your ESP category, there are times when the first set of responsibilities takes precedence.
2. Connect with others in your job description
Join your professional organization. This allows you to meet other educators from other districts who are doing the same jobs to share strategies.
3. Establish a personal connection
Indeed you have to observe the limits of professional parameters but find ways to connect with the student or group of students you are assigned to work with. When there is a personal connection, it is much easier to establish a thriving relationship. Do you share a similar culture or favorite pastimes or sports? This gives the students a chance to see you in a different light and create a bond, which comes in handy for managing classroom behaviors efficiently.
4. Have a growth mindset
Membership in one or more groups may provide a newsletter, website or social media groups which provide opportunities to learn about the latest research and practices for you to use in your classroom. This puts you in a better to do some activity modeling for the curricular lesson. Depending on your relationship with the teacher, you may even be able to contribute to activities to deepen and revitalize the curriculum.
This goes without saying that you are in a supportive role in the classroom. There are various ways that you can support the teacher. The most important way is by being an asset that the teachers and others see as having leadership qualities. You too are also an educator. You will make yourself more invaluable by having a mindset of growth, growing professionally, and developing interpersonal skills.