If you are wanting some very large and/or unique and custom, go for it. If you are doing it to save money, you won’t. The costs of materials wood, glue, screws, staples, screen, hinges, and maybe tools are gonna send you way over the cost of buying a commercial large screen cage (4-ft or so). Otherwise you are on the right track sealing it.
I’ve always been disappointed when go too hard into diy cages. Talk about HEAVY also!