Here I have listed jQuery selectors, their meanings and their equivalent javascript code to replace. Also, when code gets repetitive, I had created some util functions too which we can simply call and use.
Check out util functions: To create some for your code, you can create a global variable (if needed) and add our custom methods in it. This saves repetition of the code and feels like you are writing a library functions which can be used from anywhere.
window.Utils = {}
Utils.insertBefore = function(elemStrToAttach, insertPlaceElem) {
var elemToInsert = SwymUtils.createElement(elemStrToAttach);