Summarize the following:
Apply silicone caulk to any cracks around your windows and doors or along the foundation of your home.  Most spiders will sneak into a building through these various cracks and unintended openings. Sealing the cracks will prevent the spiders from coming in. You can purchase caulk from a hardware store. Follow the instructions provided on the label to prepare and apply the caulk correctly. When you apply the caulk, make sure that the cracks are completely filled and covered. These are the other types of passageways spiders use to invade your home.  Weather stripping and door sweeps will seal the gaps left at the bottom and sides of your doors and windows. Door sweeps are especially important because you cannot use caulk to cover the crack at the bottom of the doorway, making a properly fit door sweep your only means of cutting that path off from spiders.  A tight-fitting screen is also an essential tool. Spiders can slip in through the gaps left by loose screens, and so can many insects spiders like to feed on. Install screens over your windows and vents. Repair any holes in your screens as soon as you spot them. If you spot a hole in your screen, repair it or replace the screen. Otherwise, spiders and insects may find their way into your home through that hole. Spiders gravitated toward clutter inside a building as readily as they do outside a building.  Do not let piles of clothing, papers, towels, linens, or shoes sit on the floor. If you do leave a pile of clutter on the floor, shake out each piece of material as you clean the clutter up to shake off any unwelcome spiders. Spare clothing, holiday decorations, extra linens, and other objects that belong in long-term storage should be stored in sealed containers to prevent spiders from sneaking in.  Do not use cardboard boxes. If you must rely on cardboard boxes, however, cover all exposed openings with packing tape. Good storage methods are especially important for items stored in a dark basement or attic. Consider storing outdoor tools and sports equipment in sealed storage containers, as well. This includes roller skates, gardening tools and clothing, ski boots, and team uniforms. If you do not want to store these items in plastic bins, store them in a large plastic bag with a tight seal and no holes.  Cover all sources of pet and human food. Spiders are not interested in human and pet food, but insects that spiders feed on are very interested in these food sources. As a result, keeping food hidden away in sealed bags and containers will attract fewer insects, thereby attracting fewer spiders. You should regularly clean your general living area, but every couple of weeks, you should also clean around the areas where spiders like to dwell.  Vacuuming and dusting removes both full-grown spiders and egg sacs, preventing the latter from hatching and producing a vast quantity of baby spiders. Vacuum under furniture, inside closets, under heaters, and around all baseboards. Dust high wall corners and other areas prone to little human or pet activity.

Summary:
Seal cracks in your walls. Install tight-fitting screens, weather stripping, and door sweeps. Clean away clutter. Place storage items in sealed plastic bins. Dust and vacuum regularly.