well, as above, big costs are often venue(s) and food—so anything like a free or cheap space (family or friend’s yard, local community center) or potluck, uncle who cooks, or bulk food from Costco or a cheap restaurant will save lots of money.
as you’ve probably noticed, all that depends on the size of your wedding.
of course if you’re planning on a fancy dress, a big diamond, an expensive band, or buckets of flowers, than those will be big too. otherwise there are a lot of smaller costs, so i guess i’d recommend focusing on the biggest ones rather than scrimping and worrying about officiant fees, shoes, candles, etc—at least in the first stages of planning.
there are several books on the topic, which you can browse through in a book store and see if any would be useful for you to buy—such as Priceless Weddings under $5000 (which my cousin, whose California wedding was under $5000, swears by)
there are also lots of websites devoted to this or with lots of DIY ideas – http://theknot.com/, http://www.herecomestheguide.com/, http://www.frugalbride.com/, and you can google for plenty more. i found this one – http://www.costofwedding.com/ – particularly interesting because it breaks down the average budget, and you can look by city (a HUGE difference). i was surprised at first to learn where all the money goes, and looking at more detailed break-downs in books really helped us establish a more complete and accurate budget.
we didn’t want to exclude people who wanted to come, and we didn’t want to have people fly from around the country just to have one afternoon together, so we’re currently working on exactly these issues in planning our relatively big-group weekend-long celebration…..
so we decided on a few things that were high priority to us (the people, good music, good food) and removed or seriously cut back on the less important (general formality (which affects everything from invites to clothes to linens), mainstream locations, flowers, expensive rings, expensive honeymoon).
and don’t bend to all the social pressure you might face!! just say no!! =)