@indecisivebride89: I have some very good news for you — two or three pieces of good news, actually.
The first is, that there is no such thing as “wedding etiquette”. There is just “etiquette” — which is to say good manners and social conventions — and it applies to all aspects of your daily life. Assuming that you are reasonably polite and reasonably sophisticated, you are perfectly well accustomed to the range of etiquette that prevails in your family and your social circle. For a special event like a wedding, you should appy the highest standards from within that range. But you should not aim for a level of etiquette that is unheard-of in the circles you frequent: that would be phoney and pretentious. So, you can use that standard as you consider whether and how to send save-the-date notices and invitations: do you send save-the-date notices at all for special events? Are emailed invitations the highest standard in your social circles?
The second piece of good news, that comes as a surprise to many brides, is that etiquette applies to all levels of formality, NOT just for the snootiest of aristocratic events. You can be impeccably proper while being informal. “The highest standard” of manners means the kindest, the most generous, the greatest attention to detail, the most personal — NOT the most formal. Levels of formality are simply a matter of taste and style. Good manners demand that a hostess be consistent in setting the level of formality for an event, so that her guests know what to expect and can adapt their own level of formality accordingly. Invitations worded in the stilted third-person language most people associate with weddings, engraved on stiff white card, indicated the highest level of formality. Informality is communicated by using natural language on your regular letter-paper. Both are equally proper. Mixing the two, and hence sending mixed messages to your guests, is less proper. The more confusion your invitation creates for your guests, the less proper it is.
But, along those lines, let us stop for a moment and consider just what your “regular letter-paper” looks like. Mine is french-folded heavy white rag paper with and interleaved “A.P.” centred on the front folio; and I actually send letters on it once or twice a month. My darling grand-nieces and grand-nephews, and for that matter most of my nieces and nephews, on the other hand, haven’t used paper to send a letter since the dawn of the twenty-first century. Their “regular letter-paper” is email. And I have to admit that when I send a paper letter, I frequently use a ball-point pen instead of the proper fountain pen that *my* great aunt would have insisted was the only “proper” implement with which to write social correspondence. Times change. Fountain-pens replaced quills and india-ink. Ballpoint-pens replaced fountain-pens. Keyboards have replaced ballpoint-pens. If you decide to resort to email, the only Bees who are truly entitled to look down their noses at your choice of technology are the ones who still carry a pen-knife for trimming their own goose-quills before dipping them in the ink-bottle. If you do decide to go the informal route, your invitation would not be worded “Miss Indecisive Bride / requests the pleasure of the company of / Mr and Mrs Guest &tc”. It would be worded more like “Dear Auntie May and Uncle Ben / John and I plan to be married this summer, and we are hoping you will be able to join us for the ceremony and party afterward … (details)…. / your loving niece, / Indecisive”.
Now, the third bit of good news. If you do decide to go the very-formal route with paper invitations and all the trimmings, it is a happy coincidence that the very most formal forms are also among the least expensive! “Most formal” does not mean “most expensive”. The most proper invitations are hand-written in black ink on plain heavy white paper. Cheap thin white paper is almost as proper. For brides who cannot hand-write that many invitations, formal etiquette allows them to use *engraved* invitations instead; but invitations that are merely printed, or letter-pressed, or thermo-engraved are a significant step down in formality from hand-written invitations (especially if you use india ink). The most proper “save-the-dates” are none at all: they are a practice adopted from the advance-advertising in the convention industry and, as Ivelanded points out, are a money-making innovation for print-shops. Guests that need advance notice to arrange vacation time or travel are, if you wish to stick to formal etiquette, provided with that notice in hand-written individual personal notes. “R.s.v.p. cards” and other enclosures are eschewed by those who adhere to the most formal standards, as in social circles where such formality is routine, guests are expected to know that replies should be sent at once, in writing, on their own personal stationery with its own matching envelope and stamped by the guest’s own stamp.
Happy wedding planning! As long as you put kindness, generosity and personal care for your guests at the forefront of your planning, you will not go badly wrong.