You only get one shot at a first impression. That fist impression that we are all so worried about shouldn't stop at the curb appeal, it really should carry to every room in your house. This is your chance at you first impression as you walk through the front door.
1. Think Clean
Paint the ceiling (white) and maybe some color on the walls. If the space is small use a lighter color paint, if is a large space you can use a little darker bolder colors. How about some new lighting? Possibly some inexpensive outdoor lighting?
2. Clean all the woodwork
Deep clean all the woodwork including the floors with a good oil soap or they do have some polish with color added to cover up nicks and scratches. Or repaint if already painted. Don't have wood floors? There are a variety of floor coverings to choose from peel and stick vinyl squares to area rugs.
How about a bench that doubles as storage, or maybe a halltree that has many uses such as a bench, coat / hatrack, and an umbrella stand. How about a key hook.
4. Mirror and shelves
How about a mirror for that final check before you head out the door, or a book shelf or just a shelf to put those small personal items that go with you everywhere you go. Maybe you have space for a small inexpensive table that can have a welcoming vase of flowers, some books.
Often you can create the illusion of a foyer by using a table or a couple of book shelves. Its alright to be creative but be causious to not overcrowd.