The best way to utilize the trike when tamed or untamed when tamed it can gather loads of berries for you or when it's untamed you can use it as a shield for instance like a carno is running after you and there's a trike try to run for the trike to get the carno to fight the trike so you can escape unharmed
I can not stress enough to my friends how useful the trike is. Early game it makes a great pack animal. Late game in groups of three or four it can be used as a decent battle mount. Taming a trike early on can be a great way to start a large base and keep you well fed with berries.
Trikes are a great harvesting mount for berries and thatch. They also have good attacks (which do knockback to smaller dinos.) My favorite attack is the charge attack. I use it to raid wood/thatch bases. Overall great mount!