Traditionally viewed as “coming of age” birthdays, 18 and 21 are landmarks in a young person’s life. While turning 18 is more significant in the eyes of the law, most notably allowing an individual to buy alcohol, a 21st birthday was always held, in years gone by, as the most important milestone.

Nowadays, both are notable birthdays. However, you should “select” one for more generous birthday presents and large celebrations. It is unrealistic to expect family and friends to go extend their generosity twice in three years.

■Independent Parties

Many 18ths and 21sts are celebrated independently, away from parents and family. Some choose to have a meal out with friends or an evening in the pub; many turning 21st, as already being away from home, prefer to celebrate in their universities.

◇It is always a popular move if parents offer to help finance any celebrations, even if they are not present. This may be contributing towards a meal, or putting a (limited) tab behind a bar.

◇Parents should ask their daughter or son how their contemporaries have celebrated and establish a suitable way to contribute.

◇If parents want to make sure that the money goes towards the party and guarantee that all is above board, then they can telephone the restaurant or bar in advance and establish with them what is being contributed.

◇It is wise to limit any financial contributions and make the host (daughter or son) aware of this in advance.

◇Some parents also set up arrangements to pay the establishment over the phone on the night, or ask their daughter or son for a receipt to ensure they retain control over spending.

■Informal Parties

If your child wants to throw an informal party for his/her friends, you will probably find yourself deeply involved. Your child may well still live with you (so his/her home is your home), or—even if he/she is away at university etc.—may still regard the family home as his/her personal property.

In an ideal world, you should organize the party in another venue (hotel, club, bar etc.); but in reality, this is an expensive option which not everyone can afford. If you do feel obliged to offer your home, take some simple precautions:

◇If at all possible, make the garden the focus of activities (bad news for those with winter birthdays).

◇Remove all valuable or breakable items, roll back carpets, or cover them with old rugs or carpet offcuts. Drape light-colored upholstery with throws (or even sheets).

◇Keep certain rooms (e.g. your bedroom or study) off-limits. Put a No Entry sign on the door, and lock it if at all possible. If you can’t lock the door, drag a heavy item of furniture in front of it—it will at least act as a disincentive.

◇Supply the drink, or at least supervise the purchasing of it. Stick to wine and beer—no spirits, and no lethal fruit punches (often they taste innocuous but are extremely strong, with predictable results...).

◇Provide plenty of stodgy food—rice, bread and baked potatoes, or pasta salads are all ideal ways of soaking up the alcohol.

◇Impose a curfew—i.e. an agreed time when the music stops and the guests depart. Then warn the neighbors...

◇If you’ve got the nerve, go out for at least part of the evening; no self-respecting party host is going to appreciate the specter of his/her anxious parents in the background. But don’t stray far from home; you’ll need to be on hand if there’s an emergency or a dispute with neighbors.

■Formal Parties

Some families choose to celebrate an 18th or 21st with a more formal celebration, such as a marquee party or an event in a hired venue. Parents should always check with their daughter or son that this is what they genuinely want, rather than using it as an excuse to indulge in celebrations they would like. For some 18- or 21-year-olds the idea of such lavish attention may only cause worry, embarrassment or possible resentment.

If, however, a large formal party is the order of the day, then careful planning, involvement and organization of all family members is important. Parents should listen to the wishes of their daughter or son to ensure the party is a success for everyone.