Your hands, elbows and head are the three primary line of defence. Every time you extend your arm to tie-up with your opponent, you extend your arms to tie-up with your opponent, you break down your defence and expose your body for an attack. The purpose of any tie-up is to set up for a take down.
When you tie-up, you have to move your feet at the same time.

Wrist control

Learn how to grip your opponent’s wrists to get past his lines of defence and gain access to his body to complete the take down.

Two-on-one control

Grab one of your opponent’s arms with both hands and pin his arm to your chest . This makes his arms a part of your body, so he is forced to react to your movement. This is a low-risk control position which allows you to execute the take down without exposing yourself in the process. As for MMA, this move leaves you exposed to your opponent’s strikes as both your hand are tied up.

In MMA situation, the under hook is a more useful tie-up.

Collar tie

The collar-tie is very ineffective as you’ll often see tow wrestlers hooked together, with collar ties, pushing each other back and forth. In order to be effective in collar-tie, you have to move your feet to force your opponent out of position.