Invitations

Your guests should receive their invites and let you know they're coming at least a week in advance.  

Invitations   
- letter: classy, formal, but a bit expensive! 
If you're creative you can have fun designing  your own original invitations.      
- email quick and effective (and you can always attach an invitation)
- text: lazy and not very official, but if it works...
- word of mouth: not recommended - you want to know roughly how many people are going to  turn up on your doorstep! 

Don't forget
- why you're having a party, if there's a reason (so that they'll know to bring presents if it's for a birthday!)     
- the time and date      
- address and directions (include a map, parking details, nearest station etc)      
- dress code  
- if you want them to bring anything (bring a bottle, snacks, a dessert etc)