If you want something less fussy than net curtains - and these days most of us do - how about frosted window film? This film is sticky on one side and gives a smart, contemporary finish both inside and out.
The effect is the same in daylight and at night when the light’s on in the room, giving you total privacy. The main disadvantage is that you can’t see through the film, so while people outside can’t see in, you can’t look out either.
Frosted film works really well on sash windows when confined to the lower sash, but if you don’t have sashes, you can frost just the lower part of the glass, leaving some unobscured so you can look out.
Another option is having a design, such as rows of cut-out circles or squares, incorporated into the film, which makes it more interesting and allows you to see out (and people outside to see in) a little.
Patterned frosted-film sheets are much more expensive (and usually harder to fit) than plain ones, though.
Plain film is straightforward to fit, although trimming it and smoothing it out on the glass can ruin it, so you have to be careful and you may get through a few pieces before getting the hang of it. Don’t be tempted to use frosted spray paints instead, as it’s hard to get an even coat.
Blinds are another popular solution to privacy problems. Although fairly expensive, bottom-up blinds are the best ones to use. These are roller blinds that go up from the bottom of the window, rather than down from the top, so you can cover as much of the glass as you want. Go for a sheer fabric and you’ll be able to see out, but people outside won’t be able to see in (unless the light’s on).
Again, bottom-up blinds are straightforward to fit. You simply screw in brackets on the windowsill to hold the box housing the blind, pulleys at the top for the cord that raises the blind, and a cleat at the side to secure the cord when the blind’s up.
Some people like Venetian blinds because they give privacy during the day (providing the slats are angled the right way) and at night (providing the slats are closed). However, Venetian blinds have been superseded in the style stakes by plantation shutters, which work in a similar way but look more elegant and up to date.
Usually slatted, like Venetian blinds, plantation shutters are fitted to the window and so block out more light than blinds when the slats are closed (providing the shutters cover the whole window). However, they let in less light when the slats are open because they have frames around them, unlike Venetian blinds.
That said, plantation shutters come in panels, so you can fold them back out of the way if you want to. The shutters are made of wood or faux wood (faux-wooden ones are great for kitchens and bathrooms) and although they’re not cheap, they will enhance the room and even add value to your home.