In movies and popular culture, musketeers are shown as sword-flaying heroes in close combat, when obviously their role was to fire muskets, usually from a distance; albeit a short range, within 200 metres.
They are also usually portrayed as elite fighters, when in reality, large groups of poorly-trained musketeers were needed in a battle. The accuracy of these pre-rifle weapons was lacking, and a sizable squad of musketeers was needed to increase the chance of hitting a target.
Armies around the world used muskets; in Europe, Russia, India, China, throughout the Ottoman Empire and the empires of Spain and Britain, as Old Sam illustrates. Those firing them were by definition musketeers, not very accurate and replaced in the 19th century by riflemen.
After the French Revolution (described well in Victor Hugo's 1862 novel Les Misérables) the royal guard were to become redundant and Alexandre Dumas wrote Les Trois Mousquetaires, a historical novel that portrayed The Three Musketeers in a flamboyant and romantic light.
It's true art to show killers in a romantic light, especially musketeers. They were no doubt tough and smelly, whose job it was to attack or defend on the orders of their leaders, by blasting the life out of equally illiterate soldiers who were following the orders of their leaders. But that's war, folks. Blood and guts. Not romantic.
Novels, on the other hand, are written to entertain and shouldn't be used to find out what musketeers were actually like. (If interested, read French Musketeer 1622-1775 Chartrand, Rene (2013) Osprey Publishing. ISBN 9781780968612.)
But old artwork and museums do give a clear description of at least one emblem, which we call here the Musketeer Cross. (Click any image to enlarge.)
It's a Fleur de Lis Cross, or course, in front of a sunburst. Interpret that as you wish, but most likely the dark blue background and the fleur de lis are supposed symbolise royalty, which has the backing of Christ, symbolised by the sunburst behind the cross.
So this could be the symbol for your fancy dress party, if that's what brought you to this page.
But please don't take a musket; they typically weigh about 5 kg (10 lbs) and at 155 cm (5 ft) will get in the way of your dancing.