We are flexible with payments and work with well defined milestones agreed by both the parties. Our standard milestone plan is as following for fixed amount assignments:
1.Upfront amount (30%)
2.Create design layout with inner pages and get them approved from client (30%)
3.Perform coding (30%)
4.Testing and Bug Fixing (10%)
You need to escrow the full amount of the assignment after hiring but release first milestone as an upfront amount and rest as per the work completed for that milestone.