1. Seal all cracks and crevices well. This includes sealing openings around pipes and grouting tiles in the kitchen and bathroom especially. Also, don't forget to shut all cabinets and drawers tightly.
2. Don't leave food out in the open. Even your pet's food bowl should not be left uncovered overnight.
3. Keep all foodstuff in airtight containers in your refrigerator. You could also wrap them in foil.
4. Clean up the kitchen platform as soon as you finish cooking. Make sure to clean the inside of the microwave or oven everyday.
5. Always shut the lid of your dustbin so that insects and rodents don't have a field day in there. In case the garbage man doesn't turn up, dump the trash and don't keep it till the next day.
6. If you are planning to leave the unwashed dishes in the sink overnight, soak them in soapy water so that the dirty dishes are not exposed.
7. As lovely as it might look, keeping fruit bowls uncovered on your dining table will attract fruit flies. Use a netted cover for the bowl to keep the fruits safe from insects and prevent them from rotting.
8. Always clear the dining table and the area around it of crumbs.
9. Dispose or sell old newspapers every fortnight. Keeping piles of newspapers invites cockroaches.
10. De-clutter your home every fortnight. Hoarded stuff allows dust to collect and makes a great hideout for pests.
11. Clean all drains once a week and put naphthalene balls on the lids.
12. Use mosquito nets or window and door shields that are designed specially for the purpose.
13. Avoid placing wet towels, clothes, etc. on your bed or sofas. You don't want to be bitten by silver fish.

If this doesn't work, you could try insect sprays or better still, call a good pest control service.