Something very easy to apply and very effective is
Ortho Home Defense Insect Killer...you can buy it ($10-15) at WalMart, HOme Depot, Lowes, Rural King...anyplace and it comes pre-mixed and with a spray wand. We spray twice a year all the corners and side floor moulding areas in all the rooms to include the kitchen, bathrooms, and lanai areas..and this stuff works great.
Is is also effective for outside areas such as door entry ways, garages, windows or just around the outside of the perimeter of the house. OUtside you may need to treat the areas every 3 months due to the rain and other elements effecting the sprayed areas.
Scotts Ortho Home Defense 1.1 Gallon : Rural King