好准备吃住is normally used after, 提前通知我，好准别吃住。 提前通知我，means please inform me before you arrive, it is easier for me to prepare for accommodation and food. 随你的便：means all depends you. You decide. Or we say, select what is convenient for you.

好准备吃住 is not correct.Maybe 准备好吃住。It means preparing for living and eating. 随你的便 means 'by yourself'.This phrase contains angry or some bad mood, but not absolute.

好准备吃住：比如说有外地朋友打电话跟你说准备到你家，你问他什么时候来啊，好提前给他准备吃住。 随你的便：你朋友跟你客气说不用帮他准备了，他自己可以安排。你就可以用随你的便回答。