A baby shower is a very special occasion and so naturally it is only fitting that you would want to formally invite your guests. So, unless a baby shower is being planned as a surprise or is being arranged rather quickly, then a written invitation is almost always the most appropriate method to use. Where this is not possible then personally inviting guests by telephone is acceptable but e-mailing your invitations should be avoided despite the fact that they might appear to be convenient and fast.
As long as your budget allows then your shower invitations can be custom ordered although this is really unnecessary and there are a lot of very good pre-printed invitations available locally or on the Internet. Alternatively you can always make your own shower invitations if you have the time and a little bit of artistic talent.
As is the case with any invitation to a party your guests will need some basic details such as the name of the person for whom the shower is being given, the name of the host, the date and time of the shower, the location and instructions on how to reply.
Another thing to consider including is details of any theme for the party or the shower gift registry and this can be a little bit tricky as many people feel that this is presumptuous and puts undue pressure on your guests. Naturally this is a matter of personal choice, but one answer which usually works is to leave this off your invitations, request you guests to reply by telephone and then than slip this artfully into the conversion if guests do confirm their attendance. Do not forget though that you will need to have this information on hand when your guests telephone and etiquette says that you should only give out your shower gift registry information if your guest requests it. If your baby shower is to be a formal event then you cannot go far wrong if you keep to etiquette but, if your shower is less formal and includes just close friends you can probably get away with relaxing the rules a bit.
The timeline for a baby shower is very important and the greater the notice your guests are given the better. Accordingly, you should aim to mail your invitations out 4 to 6 weeks ahead of the shower date and this is especially important if out of town guests are being invited. If this is not possible then you should certainly aim to get your invitations out at least 2 to 3 weeks before the party. Advance notice allows your guests to organize their diaries, reply and shop for suitable gifts.
It is also important that you request your guests to phone you and let you know whether they will be coming. With everything involved in planning your shower the very last thing you want to do is to have to telephone around to find out if some of the guest plan on attending. However, there will usually be some guests who do not reply and so one week prior to the party date you should make time to call those individuals to ascertain their intentions. Having accurate numbers will help a great deal with making the arrangements for your very special day.