KNOW YOUR LIMITS
This applies to a lot of different aspects of wedding planning, such as budget and personal time and energy. Making, and sticking to, a budget will help alleviate unnecessary stress by forcing you to make the right decisions for your wedding. Again, ask yourself what truly matters to you and focus the biggest chunks of your budget on those parts. Thinking of doing a lot of DIY for your wedding? That's great! Just keep in mind that a lot of DIY means a lot of time and energy to create said DIY pieces and then organizing to set everything up. Before committing, know how much time and energy you really have to spend towards this. Again, there are so many limits when it comes to your wedding day. Make a list of all of the ways you could be pushing the limits (budget, personal, policies, guest count, spatial needs, etc.) and come up with ways to avoid pushing them too far.