These are some common iMessage emoji substitutions you can do.

TextEmoji
:)🙂
:-)🙂
:D😄
:-D😄
:(🙁
:-(🙁
;)😉
;-)😉
:o😮
:-o😮
:p😛
:-p😛
:*😘
:-*😘
>:(😠
>:-)😈
B)😎
B-)😎
:'(😢
O:)😇
O:-)😇
<3❤️
</3💔
^_^😊
-_-😑
>_<😣
o_o😳
\o/🙌