Let me preface with the fact that I am not located in Virginia. Also, in giving suggestions I am assuming you are acting as an advocate now (not as a parent) since your children are grown.
You could try to make changes in two ways. One way is as an individual advocate on a case-by-case basis. School districts have some latitude on how they run their IEP process, BUT they must do so within the confines of the IDEA and state laws/regulations. So look up the state statutes regarding special education and go to the Virginia State Department of Education and read any polices, state plan, parent guides/resources, etc. they have on the special education process. If laws are not being followed or procedural errors are being made you can try to nicely point out their compliance "issue." For instance, what does Virginia require in terms of days' notice for meetings and are they following that? If not, you could state "it is my understanding that parents were to receive 5 days notice prior to a meeting." If they insist on parents signing a PWN at the end of a meeting, state "it is my understanding that parents have 10 days to sign the PWN." And have your documentation from the department of education's website ready.
If the school district is following all laws and compliant procedurally but still being difficult, that requires different tactics. Once example I can think of is providing a copy of the draft IEP prior to the IEP meeting. Some school districts may flat out refuse to do this or may only send it 24 hours in advance. In the case where they refuse to send a copy, respond to that denial stating "in that case, we will need two IEP meetings in order to give my client time to review the draft IEP and make suggestions so that she may participate meaningfully in the process [which IS required by law]." If you ask for the draft IEP 5 days or 48 hours in advance, and it isn't sent until the day before the meeting, respond that "I'm sorry you were unable to provide us with a draft within the time we requested. Due to my client's schedule and needing time to review this document, we will need to reschedule the meeting for a later time."
If you're hoping to make more system-wide changes, that would require more of a group effort, such as starting a Facebook page or something along those lines that would connect parents and get everyone on the same page as far as what changes they want to ask for. Although it would be seen as confrontational and "going over heads," as a last resort, you could get a group together to go to a school board meeting.