It's the time of year when we're all thinking of putting the heating on – and trying to avoid it if at all possible.

[Read more: Upgrade your boiler: 5 tips for a better heating system]

But as well as wearing extra layers around the house, there are plenty of ways that you can keep yourself warm before you finally have to turn the boiler on. Here are a few ideas:

1. Open doors

Of course you need to keep any windows and internal doors closed when it’s cold to keep heat inside. However, some doors can actually be left open to increase the heat. When you put the shower on or run a bath, for instance, leave the door open and let the heat and steam circulate.

The same goes for the kitchen after you've been cooking - leave the oven door open after you've used it and make sure the doors to adjoining rooms are open too.

2. Draughtbusters

You'll keep the house much warmer if you stop heat escaping through gaps and cracks in walls, as well as under doors and through keyholes and letterboxes.

Some gaps are easy to spot, but don't forget the areas where pipes or cables go into walls, behind the washing machine, under kitchen cupboards and around sinks and toilets. If the gaps are out of sight, sealing them can be done easily with scrunched up newspaper and plastic bags, or old socks.

But for more visible areas, sticky draught excluder products are available in DIY shops, as are keyhole covers and brushes to insulate letterboxes. You could even try stuffing cotton wool or cling film into the cracks with tweezers, and attaching a thick fabric flap over cat flaps.

[Read more 5 ways to make your heating work harder]

3. Sock it

Fill a sock with rice and perhaps some fragrant smelling spices or lavender, tie the end in a knot, and heat it in the microwave for a minute or two to create an instant heat pack. It’s much cheaper than a shop-bought wheat bag – but be careful not to overheat it.

Alternatively, you can pick one up from John Lewis for £12.50.

4. Bubble glazing

If you don't have double glazing, bubble wrap and plastic sheeting over windows provides home-made insulation. Dampen the windows with water from a spray bottle, and then cover the glass with cut-to-size pieces of bubble wrap, which can be bought cheaply online.

Finally, cover the entire window (including the frame) with clear plastic and seal it with removable sealant or silicone. It might not look great, but that's a small price to pay for keeping warm.

5. Chimney balloon

If your fireplace is only decorative, you could use a chimney balloon to stop heat being lost up the chimney. The balloons, which are made from a special laminate and can be bought from DIY shops for around £20, should be placed just inside the chimney hole and inflated to block incoming cold air, and keep room heat in. Just don't start a fire without removing it!

Try Wickes' Universal Chimney Pillow, £13.99 or check out Amazon's extensive range.

6. Cosy curtains

Either sew or clip a thicker fabric to the back of your curtains, or hang it straight from your curtain rod. This adds another layer of insulation which won't change the look of your curtains from the inside, and shouldn't be too obvious from outside if you only close them after dark.

And it's not just windows that need curtains - placing a curtain in front of doors to the outside adds another layer of protection too.