Yup. I've been slowly learning on how to educate clients about this. The biggest thing is quoting. After you sit down with a client and discuss what they need, most people are quick to throw a number out there. This is one of the worst things you can do.
Instead, I lay out a page that has a brief overview of the project and objectives, the technical details (8 web pages, 1 contact form, hosting, new domain, email, no email, a database, mobile first, whatever), and then break down the cost really intensely. Each stage must be completed and paid for before the next stage happens. By doing this, the client starts to realize the scope of work and the dedication I am giving to their project. It also prevents the another too common occurance: a completed project with 'for placement only' images and copy because the client has yet to provide those items.
Upfront deposit: Usually around 10%. This makes the client realize this is real. This happens after the meeting, after this quote / scope of work is given, before I start real work.
Planning / Research / Asset Collection: This stage consists of planning exactly how everything will work: IA - navigation, hierarchy, flowchats, wireframes, personas (sometimes), etc. This is also where they have to give me photos and copy and pay me again. Until I have copy, photos, and money, I don't move to the next stage. I usually require 20% here.
Design & Development: Sometimes I break these up separately, sometimes I don't. Sometimes I require payment after both, sometimes I don't. Depends on the project. 40% payment here.
First round of revisions based on client feedback: I define revisions very carefully in the initial project objectives so that if they change the entire scope, we start from scratch and re-do pricing. I don't ask for money after this round typically, unless the scope of work changes.
Testing, second round of revisions, cleaning up, delivery, tying up the lose ends. Final payment of 30%.
Any revisions beyond what I defined in the original scope is charged for. Typically, I include 2 or 3 rounds of revisions in the price. I define a revision as a set of changes that have no effect on the number of pages, cause a complete redesign, or changes the objective of the project. Things like changing copy or images, moving elements around, and making colors darker are examples of revisions. "Hey, actually I just realized I want to have a new page in the top navigation" = $$$. Adding a link to their brother's facebook in the footer would be fine. By giving concrete examples of what a revision is and isn't, the client doesn't have to guess as much and they like and trust you more.
Building trust with your client, educating them, and giving them the information to be intelligent has a great effect on the relationship. So many times I see people bitching that their dumbass client wants them to change the entire top navigation and menu and they don't know how much work that is and they have to do it for free. The client is only a dumbass because you didn't tell them how much work a change like that required, and you have long lost the opportunity to ask for money in due to scope changes.
The other thing I see people failing to do is breaking down the price by hours. I decide how much money I want for the whichever phase, decide what my hourly rate is, and then divide to get the hours. I increase the hours by 15% (us designers - we alway underestimate both the time things take and the value of our work) and then add the money back up. I might say it's 25 hours at $30/hour for planning. 30 hours at $40/hour for wireframes. Etc. This also makes that big ass number at the bottom look much smaller. If you charge $10k for a website (or video or whatever freelance project you have) and break it down so that every individual charge is in the $500-$1000 range, people are ecstatic to pay you. If you throw the $10,000 number at them they wonder where their money is going and think, "holy fuck that is expensive."
Since I started taking the time at the beginning to plan and educate clients I've had so much better luck getting paid and getting things done without ripping my hair out. It's amazing. It also weeds out all clients who aren't serious about a project and therefore it doesn't waste either of our time.