Get all your drinkware at Party City! Plastic is not rude! [Via]
Guest List
Hosting a party means treating guests to anything they may enjoy within the party–meaning if you’re offering it, it should be free. That goes for food, drink, entertainment, knick-knacks, etc. [Uncommon Courtesy is split on the concept of pot-luck weddings. Jaya thinks they’re okay as long as you make it clear and are ready to field questions and concerns, Victoria thinks they’re terrible.] Yes, there are areas where cash bars and things of the sort are more accepted, so YMMV, but really we’re going to take a firm stance on this. Don’t invite 200 people if you can’t provide for 200 people. Don’t invite 5 if you can’t provide for 5 either. This might take some hard negotiating, but sometimes that’s what wedding planning is about.
Food & Drink
Most people think that the only way to have a “proper” wedding is to do a sit-down dinner (and then pass the costs onto your guests if you can’t afford it) but that’s just not true! You can host a brunch reception, or do cake & punch, or passed hors d’oeuvres. You can just do beer and wine instead of a full bar, or do a taco buffet. If you eschew a full sit-down meal, you can also often accommodate more guests. Just make sure that there are actually places to sit for the elderly/easily tired, or surfaces on which to place food. It’s never easy to drink with one hand and balance a plate of appetizers with another.
Timing
This is slightly related to food and drink, because the time of day you have your reception will influence what you serve. It’s generally considered polite to provide a meal if your reception is taking place during an assumed meal time, and since lots of people have receptions that take place from roughly 6-10, that means an actual dinner will need to be served. You do not have to do this, but if you hold your reception during dinner time, you should make it extremely clear that a full dinner will not be served, and be ready for some people to bail so they can find pizza.
However, if your reception is from 3-6, that frees you up to serve some light snacks and drinks, and many venues will give you a discount for not using the space during “peak” times!
Decor
Similarly to the idea that you need a sit-down dinner, a lot of people assume you need fine china and flatware. Yes, it feels nice, and you don’t want someone trying to cut a steak with a flimsy plastic knife, but there are a lot of great looking plastic/paper utensils out there. As long as everyone has functional enough tools to eat, the rest is just a matter of taste.
Invitations
Etiquette doesn’t care if you have a hand-inked suite with individual, foil-lined envelopes and tissue paper between each page. It used to, but it doesn’t anymore, because we’re all sane people who understand that paper costs money. Instead of an RSVP card, ask your guests to email RSVP. Instead of a separate card telling your guests about accommodations and directions, set up a wedding website and ask them to get the details there. Also, there are plenty of websites that offer gorgeous, customizable invitations without having to pay for a calligrapher.
Favors
Favors are not necessary! I will repeat this until it shines through everyone’s skulls like sunlight through a magnifying glass, condensing on the brain of that one aunt who is nagging you about jordan almonds. The reception is the favor–paying for food and drinks and entertainment for your guests is the thanks you are giving them for bearing witness to your marriage. They do not need to take home a jar of jam or a keychain with your names on it after that, and even Emily Post agrees that it’s not any sort of breach of etiquette not to provide them. Similarly, you don’t have to provide gift bags for guests in from out of town. Unfortunately, I think these customs have become so popular that people assume they will happen, and that you’re a bad host if they don’t. So please, help me in breaking the trend and saving yourself some cash.
uncommon-courtesy.com 
What about travel costs? A lot of our guests were out-of-towners, and all of the wedding guides said different things — some said that every guest was responsible for his or her own travel costs, while others said that we should at least comp flights/hotels for the wedding party and family who were “compelled” to be there. Thoughts?
I definitely think no one should expect you to pay for their hotel/travel costs. That is not your responsibility. Presumably if someone in the wedding party or a family member can’t afford it, they should bring it up with you before, and you work out whether you can/want to help them out. But it’s definitely not required of you.
Also, traditionally, the bride/groom paid for the accommodations of their wedding party (and often just lodged them at their family homes) but no one does that anymore.
Oh, dear God. Where do I begin?!?’
E-mailing an RSVP (or asking a guest to do this) is horribly tacky, and so are the awful QR codes and registry links on wedding invitations. Send out proper invitations. There are enough sites online that offer decent (not truly formal, but at least in good taste) examples of what you can mail out. Yes, spend the postage. If you cannot afford this, it’s time to evaluate that maybe you cannot afford a wedding to begin with.
Having a wedding with a modest budget does not mean it needs to look cheap. Good and proper decisions can be elegant, despite funds. Having a cake and punch afternoon reception is fine, as long as guests know in advance not to expect a meal (and you should do this during a time of the day when they won’t.)
Potluck receptions are tacky. If your “caterer” needs to be family members, that is fine. But don’t ask guests to bring a dish to pass. This isn’t a picnic. It’s a reception.
Etiquette states that a reception should offer something to eat and drink. It’s up to the host to decide just what kind of budget they have. Again, if you have little funds, do something in a small time window so that guests can celebrate with you and then go about their day (and get a meal on their own.)
Hosts are not obligated to pay for travel. If you can offer it, this is a nice gesture.
If you are doing a formal wedding, with proper invitations, you need to have a card included with accommodation options. Reach out to a local hotel and book a block of rooms (and no, you don’t need to sign a contract.) Guests can pay for their own room, but at least you extended a courtesy to make sure that a room block was available.
No cash bars. NEVER. No showers asking people to do a “Jack and Jill” where they bring a gift and a cash payment to help pay for part of your wedding. It’s TACKY.
Again, if you have to ask outright for cash, you cannot afford the wedding you are planning. Simple and less expensive is fine. Asking guests to pay for your dream wedding is not right.
Favors are not necessary, unless there is something that has a special meaning and isn’t horribly done. (No shot glasses with your names, please. No one needs one shot glass with your wedding date.)