One thing to keep in mind (for both the OP and anyone else referring to this thread for ideas) is the size of your chapter. When I was active, my chapter was between 10-15 members, so almost everything was mandatory. However, it’s much different if you have a chapter of 250 members. Making everything optional for a small chapter would be detrimental to getting anything done, and making everything mandatory for a large chapter would likely cause logistical issues, as well as many sisters not understanding why they have to be at EVERY single event when there are so many people.
Another option to consider: Calculate membership percentages in order to allow each sister to skip a certain number of events each semester
Let’s assume chapter meetings, rituals, and national staff visits are mandatory. This leaves you with fundraisers, philanthropies, socials, and sister development events (and perhaps a few other categories). Look at your calendar and figure out how many sisters need to attend each event in order to have “full participation”.
My chapter, for example, always participated in 4-5 philanthropy events each semester. In the spring, we held our annual pageant, which was when we needed all hands on deck. That was mandatory. So let’s say there are 4 other philanthropy events for the semester, and let’s pretend there were 50 members in the chapter. That’s 50 members x 4 events = 200 “people”. If your goal was to have at least 75% of your chapter at every philanthropy event, you could allow each sister to skip one philanthropy event that semester:
50 members x 1 event skipped = 50 missing sisters
200 “people” - 50 missing sisters = 150 “people” attending events
150 “people” / 4 events = 37 or 38 members at each event (75% of your chapter)
Also, I believe it’s already been mentioned, but when it comes to social events with other chapters (mixers, specifically), it is rude to only have a small number of sisters show up when the chapter voted on the event, and the other chapter took time/money/effort to plan for it. Again, it’s better to have fewer mixers where more sisters show up, than to have a lot of mixers where only 25% of your members bother to attend. Instead of making mixers a majority vote, you could require, for example, that 75% of your chapter must vote to have the event, and the sisters who vote ‘Yes’ must attend. You could pass a sheet of paper around at your meeting and have a ‘Yes’ and ‘No’ column. If at least 75% of your members have voted ‘Yes’, then you have the event, and you’ll already have a list of all the sisters that need to be there!
Of course, you’ll probably need 98% of your chapter members to be at the meeting to vote; yet another reason why chapter meetings should be mandatory!
Ok, I’ll stop here

Hopefully this helped!