Choose finishes that are compatible with the house and with recent sales in your price range.
Starter homes usually have a minimal amount of decorative details, easily cleaned surfaces, and carpet that can hide a multitude of stains. That generally means laminate countertops rather than tile, because cleaning the grout in tile is not a fun thing. Solid surfaces, like granite or Corian, are too expensive for starter homes and require special care. Go for vinyl flooring in the kitchen and bathrooms and oatmeal-colored berber-type carpet in the rest of the house. Look for cabinets with a minimum of details or vinyl laminate surfaces. Single-unit tub and shower enclosures are best. Appliances should be budget quality. Keep light fixtures and plumbing fixtures plain. Spend money fencing the backyard to make a child and pet-friendly place, and spend a little money landscaping the front yard so it looks like the other ones in the neighborhood. Install vinyl mini-blinds in all windows so potential buyers do not have to think about the cost of window coverings in addition to their home purchase.
Second or third homes for young professionals moving up in their careers must generally reflect some stature and style. The potential buyer feels he or she has worked hard and deserves some nice things and some creature comforts. These potential buyers may require a well-appointed backdrop for business entertaining. Spend your money in the public areas. Put some granite or marble on the entryway floor. Use crown molding in the public areas, good quality vinyl flooring in the kitchen, and laminated flooring that looks like wood in the dining room. Put a fancy light fixture in the dining room, the entry foyer, and at the front stoop. Use decorative plumbing fixtures in the powder room and ceramic tile or stone on that floor. Purchase midrange appliances like Whirlpool, GE Monogram® series, KitchenAid, or comparable brands. As always, landscape the property in accordance with neighborhood standards.
Luxury homes are not really a good idea for beginning flippers, so I am not going to cover them here. I will point out that even luxury homes cut corners in places not typically noticed by guests. I have gone to open houses for homes priced at $750,000 and up. They look pretty on the surface, but then you see that all closets have wire shelves, rather than solid wood. The windows are usually something called contractor grade, which translates to inexpensive. Granite countertops do not include granite back-splashes. The plumbing fixtures are cheap knockoffs of much better quality designer fixtures and the ceiling fans are the $29 ones from the sale bin at the home improvement store, not anything that will last for long. Drawer bottoms are usually very thin plywood, not solid wood, and the drawer glides are lightweight and not full extension.
Homes that appeal to retirees emphasize comfort, safety, security, convenience, and storage. Spend money on paddle handles instead of door knobs. Plumbing fixtures should also have paddle handles rather than hard-to-grip knobs. Choose a security system that includes a second keypad in the master bedroom. Install grab bars in the master bathroom, carpet in all rooms except the kitchen in order to provide plenty of non-slip surfaces, and use plenty of exterior lighting that can be controlled from the master bedroom and some other location. If possible, put in lazy-Susan corner base cabinets to make good use of space. Anyone over 30 or so simply cannot get down on their hands and knees to rummage around in the standard corner base cabinet.