Thank you for your answers everyone, this is super helpful since I'm new to commissioning in general. I've only been programming for my friends but that was never involving any form of payment. As for deliverable, I am definitely considering using dropbox as my primary site unless a client wants the product to be uploaded on a different site

And of course paypal would be ideal for me too.
Unfortunately, I am not on twitter at the moment. I considered using it a while back but since I was programming for fun, I didn't feel a need to make one =/. I will get a twitter most likely once I start to take commissions and everything.
As for mobile experiences with Renpy, I don't have any at the moment but I can look into it and take a day to learn everything so I will consider that as a potential commission opportunity.
I've been focusing a lot on the coding aspect of my framework and less on making it super pretty with transitions and such. But I see what you mean, I like the method of paying half first and then the other half once the work is completed. I will try to get out a general RPG framework for everyone to use and also give people a sense of what I can do. I do need to build my portfolio anyways so I might provide some free stuff as a method of showing my work.
The video is a good idea as a way to provide a preview of the product in case the client needs it changed or anything. I don't have any games out but I hope that providing an RPG battle engine would be at least enough to show how I work?
I have looked into some gui prices and I am thinking of charging less for free games over commercial although I can't code for free since I do need the money XP.
A set date for deliverables would be my ideal way of working so the client has a good idea on when to expect the product. I was thinking multiple deadline dates as a way to check in with them and ask if they want to adjust anything as well.
I am willing to do bug fixes although I don't know the general time frame for that. I will have to look into it.
I have returned after a long time away. Working on a small project, hope I'll be able to show it on here soon! =D