What is the way to establish a TCP connection?

By using 3 way handshake process, where client send a SYN packet to server. If server is ready to listen this client, it send back a SYN+ACK packet and adjusting the window size based on requirements back to the client, and then client send back an ACK packet (which is an acknowledgement packet of the SYN it received from server)back to the server. When server received this ACK back, the connection is said to be established between client and server.