Don't think you can get away with tossing on your usual black work suit at the last minute. A little more effort is required. "Weddings can be tricky affairs in the style stakes," says London-based stylist Ian Black. "If there are no specific requirements, such as top hat and tails, a more relaxed dress code leaves a greater margin for error. So always ensure you dress according to season and your age."

For summer, you're best to avoid dark colours and heavy fabrics - go for a linen or cotton suit in lighter colours - beige, light grey, blue, or if you're really daring, white. You could get away with leaving a tie at home too, but judge it by the couple's taste - there's nothing worse than being under-dressed at a wedding.

If it's a winter wedding, a darker wool suit would be your best option. Of course, you don't have to wear a suit - a formal shirt, tie and smart trousers would be fine, but better matched with a blazer or jacket. Again, it's all about knowing the couple's preferences.

An evening wedding tends to call for the most formal approach - a dinner jacket if it's really formal, white tie and cummerbund if it's ultra-formal. A safe bet is to go with a dark suit, or a blazer if it's more casual. Pay attention to your accessories - a smart ironed formal shirt, silk tie or waistcoat can make all the difference. You don't want to look like you've just turned up from the office.

"If you do want to stand out from the crowd use an accessory that can be easily removed if you're not comfortable," advises Ian Black. "Waistcoats are great for this as they can be removed or covered up easily, as are hats and scarves. If you want to be really old school, handkerchiefs and brollies can be cool - think a modern take on The Avengers."

What you really shouldn't wear: Anything that will outshine the groom (shame on you); jeans or khakis (of course); Hawaiian shirts

Contrary to popular belief, you don't have to wear black to a funeral. Nowadays black is pretty much the reserve of family members. That doesn't mean you can't, just that you're as well to go for a conservative dark blue or grey.

The mood of the day is muted and respectful - unless of course the deceased has specifically requested otherwise - so ensure your decisions always veer towards more sober than usual. That means avoid flashy ties, ostentatious jewellery (you should think about removing that diamond ear stud if you have one) and alligator shoes.

Opt for a solid or subtly patterned tie, white shirt, black socks and dark polished, leather shoes. "Think black and classic, this is not the time to be making a fashion statement," advises stylist Ian Black.

Generally speaking a tie is always best - though if the family's going for a less formal mood, a black turtle neck jumper or even black T-shirt under a jacket or black shirt sans tie are all acceptable attire. At the end of the day it's one occasion where your clothes really shouldn't be drawing attention to themselves. And whatever you do, remember to switch off your damn mobile!

What you really shouldn't wear: Novelty T-shirts; baseball caps; scruffy trainers or any informal footwear; loud patterns; checks.

This one is the sartorial dilemma that crops up every year and commonly foxes a few people. Let's erase that pre-party anxiety once and for all. If the invite says 'black tie required' then really there's no choice but to wear a dinner jacket.

That means tuxedo with silk facings, trousers with matching silk braids, black silk bow tie with white wing-collar front dress shirt, black socks and patent or highly-polished black shoes. More dressy elements such as a cummerbund or waistcoat are optional, but certainly shouldn't be worn together.

"Cummerbunds look great if you have a 28-inch waist, but for those of us with a little more around the middle it will only serve as a big colourful band to frame your paunch," warns Ian Black. "If you want to add a personal touch in a subtle way, cufflinks are the best way to go - you can totally update a look with the right cufflinks."

If you get an invite stating 'black tie optional' or 'black tie invited', you can be a bit more relaxed about things, but bear in mind most men will go down the DJ route. Either way, this is a pretty formal affair, so if you want to bypass the dinner jacket, go for a dark suit in black, navy or dark grey with a dark tie. By the way, if your date's wearing an evening dress, one of the weird rules of such things is that means you really have to wear a tuxedo.

What you really shouldn't wear: There's little room for manoeuvre here really, so just stick to the rules.