Figure out what sort of wedding you want to have
You don't have to get super detailed here, but it helps to go through the major elements of the day (location, type of venue, photography, approximate guest count, entertainment, food) and think about what you want for each item. Talk about what's most important to each you. Is being married in your home town more important than having an amazing band? Would you rather have a huge wedding or a wedding on the beach? This is also a good time to ask your families if they have strong feelings about any parts of the wedding in particular.
Estimate what you and your partner and your families can reasonably contribute to the cost of your big day
Maybe you already know what your parents can contribute, or perhaps you know they won't be paying for any of it. In any case, it helps to have a ballpark figure in your head as you being doing your initial research.
Do some research
Using the basic vision for your wedding you just came up with, start contacting vendors and venues about pricing and availability. Keep in mind that the research phase is one of the more tedious aspects of wedding budgeting as you try to figure out the hidden costs you might incur at different venues. Give yourself time to work through it all; it can take a few weeks to get information from all your potential venues and vendors. We recommend figuring out what your wedding would look like at three different price points, or figuring out three ways your wedding could look at the same price point. This is useful in the next step.
Talk to your families about their contributions
No one likes talking to her parents about her wedding budget, but it’s best to just get it over with. Plan a time for you and your fiance to talk to each family, giving them some time to prepare for the conversation. Then share what your dream wedding looks like and what you think it will cost. We recommend having all research with you. Then if they say, "There's no way a venue should cost $10,000" you can say, "Well, here's what a $5000 venue looks like...are you OK with it?" A lot of older generations have no idea what it costs to throw an “average” wedding these days.
Make your actual wedding budget
Once you know the total amount you’re working with, create a spreadsheet and enter all the aspects of a wedding you plan to include, followed by your estimated total allocations for each. Under each category, list all the items that are included in that part of the budget and give each a dollar amount. Then add a line for miscellaneous and fees, and give yourself $100-$500 in each category to account for unforeseen costs. This step will help later on when things cost more than you expected or when you realize you forgot to include something.