The wedding invitation plops on the mat. Quick mental arithmetic: how much will this outing cost, with a gift and possible overnight stay, not to mention the expense of a new outfit.
Well, it's good news on the outfit front. Weddings have become less formal, as the Celtic Tiger all-singing, all-dancing, three-day affairs with multiple outfits are now, thankfully, a thing of the past.
Guests are adopting a practical, 'I'm going to wear this again' approach to buying for what can be a stressful day out, starting with all those relatives you haven't seen for years. Then there are reunions with college and childhood friends – questions about career and love life so all the more reason to want to look 'wow', but without upstaging the bride, of course. I advocate dressing to be yourself – buy to suit your lifestyle and your budget; don't subscribe to all the etiquette rules associated with weddings, except for one... and that's not wearing the same colour as the bride.
Some elements of the fashion police frown on guests wearing black because it is a colour associated with mourning.
However I believe the LBD offers maximum scope for re-use and dressing-up potential, and it was my colour of choice for styling our fifty-something wedding guest in our shoot dressing women aged from their 20s to 50s.
Wedding guests anxious about finding a suitable outfit should start with something simple but beautiful.
In Mairead's case, it was an elegantly cut dress from Marella, the perfect blank canvas on which to layer up interest and build colour and add statement accessories.
The Caroline Issa embroidered ankle-tie shoes from LK Bennett have a delicious splash of colour and come with matching clutches in two styles. However, my secret weapons here to surviving the big day are the identical court shoe with a lower kitten-heel – you can swap them for dancing and no one will be any the wiser.
For some, the best part of a wedding is being able to wear a picture hat. The black and white checkered visor from Martha Lynn is all about drama to the back and sides and it won't get in the way for all that air kissing.
Milliner Martha Lynn won the prestigious Accessories Designer of the Year award at the Innovation Awards in Galway in March. Perspex accessories are very on-trend this season, and Martha has a number of cutting-edge perspex styles at her new studio on Baggot Street, Dublin (085 777 1641).
For Lauren, our twenty-something model, it's pretty practicality with a youthful shorts suit that can be worn again and again. The Miami South Beach print on the powder-blue blazer is repeated on the tailored shorts, which are a decent length, so they won't make Granny blush, but they will make cousins look on in envy.
If a hat's not for you, build height and drama with your hair. Stylist Charmaine Whelan from Aidan Fitzgerald in Blackrock created a sophisticated mohican with sleek sides a la Nicole Kidman on the red carpet at Cannes.
I cranked up the feminine vibe for Joyce, but her outfit remains hugely affordable. She's wearing my 'dress crush' of the summer, a €29 yellow fit and flare from Tesco. The fabric, finish and feel are quite extraordinary at that price, and with that saving, you can play around with your priorities. If you're a shoe fiend, then spend your loot on that. Joyce's cute sandals have a silver metallic strap and a yellow suede tie.
They are reduced from €299 to €199 at Fitzpatrick's on Grafton Street.
My love affair with yellow was a slow burner; if you're nervous, turn to it for accessories and then introduce it into your wardrobe by working it with white or monochrome.
And finally, for the forty-something with a great figure, I threw out the rule book completely and chose a strapless jumpsuit from Ted Baker.
You can wear a short tux jacket over it for the church or registry office and create a long, lean Spanish vibe with a straw boater.
It will look like a black trouser suit until you take off the jacket – then watch those eyes of envy follow you around the room.