Flipping Details, please respond!

I have read about flipping homes ect, I understand this but when i go to message boards i see tons of people getting stuck or just doing it all wrong. Lets say I have a motivated buyer in Michigan( where I live) I go and either get a PA with contingencies or an option contract then I go a quickly find a buyer now I have found a good title company but what about the double closing or assigment does this require the buyer to get a particular mortgage, I know it can be assigned to the buyer for usually small cash amount or whatever possible amount is agreed on but i was reading do some assign to the seller and create a lein that they have too pay back before closing and in essence our pay. My main concern is the double closing and the seasoning as well as not having to have my buyer use a certain company ect. As i said i understand quite a bit but just unclear about some details.

I’m not sure if I understood your question but…
no, the buyer does not need to use a certain company or get a particular mortgage.

I don’t think you need to put a lien on the property for your assignment. I’ve neve heard of that.

When you assign it to the buyer you add on your fee and that is their purchase price. At closing you will get your money.

I think that is how it works, correct me if I am wrong everyone.

Thats what i was wondering about seasoning it isnt always that easy if you double close. If you assign to buyer do you still go to closing or does title company take care of it or did they pay you cahs and you assigned the contract to them?
As I said more clarification