I'm working on a Master's right now. I'm also an engineer and work for a large company who will pay full tuition for a further degree in my line of work. It's tough because I work full time, but it's great because it's free. My other options were: teaching assistant, research assistant, get in-state residency and find a part-time job locally.
While shopping around for schools, I would suggest keeping a spreadsheet or document about job opportunities at each one. How do they choose TAs/RAs? Do professors pick people or does the department help organize it all? How many positions are available per year? Are there labs, tutoring groups, libraries or other campus resources that hire students or offer tuition assistance? For example, some school interview and select TAs around the time you apply to the department, while others will select them when the first term begins.
If you are still in school, go to your university's career center and ask them for information. If you already know the grad school(s) you want to go to, contact THEIR career centers too, and find out what they offer. Talk to your current and future departmental adviser. You may need to ask a lot of questions and be proactive about following up with people.
Where are you studying now? If you're in the US, look for resources for foreign nationals, recent immigrants or bi-lingual people. What hobbies do you have? Look for scholarships for that (farming and volunteering seem likely candidates for this). A career center might be able to help you find these kinds of scholarships, but you might be able to Google around for them, too. Do you like to read and write? Some organizations have essay or competition-type scholarships. I remember there was a scholarship competition when I graduated high school for people to read and write an essay on Ayn Rand's Atlas Shrugged.
What do your parents or grandparents do? If they are in a union or certain companies, you may have scholarships you can apply to specifically for children of parents in their field. I know my union offers at least on small scholarship like that.
One of my regrets is not researching schools thoroughly enough for this kind of information before starting both undergraduate and graduate degrees. Even a couple thousand earned here and there over the years would have made a big difference.
Edited to add: And don't stop applying to scholarships or campus jobs after your freshman year! Apply every year and keep seeking out more and more opportunities. The best scholarship I got in undergrad was given to me junior and senior year. I was one of few people awarded it at that age because most people stop applying after freshman year. There was a volunteer component, and I worked really hard Junior year to be involved. That got me an even bigger scholarship from the same group the next year.