Do I still need to make improvements if I decide to lease instead of sell?  The
advice for making improvements pertaining to selling and leasing are not that much different.  Tenants don't want to move in to dirty carpets, drippy faucets or a non working stove burner.  Therefore you still need to make sure that your property is move in ready, if you want to lease your home fairly quickly and appeal to quality renters.  

You don't need to hire a home stager, make major kitchen or bathroom renovations, but you do need to make sure that there are no unfinished projects and that everything in the home is nice, clean, clutter free, safe and functional.   Following are the minimum things you should do before putting your house on the market for lease:

1. Make sure all major components (roofing, HVAC system, electrical, plumbing) are functioning.
2. Take care of all safety items (non-functional smoke detectors, inoperable windows, loose railings, any tripping hazards, etc.).
3. Spruce up the curb & back yard appeal(trim the shrubs, remove weeds & dead plants, repair fences and get rid of any backyard junk). 
4. Declutter and do a thorough cleaning job inside the home.
5. Touch up paint job & repair any holes in the walls, and if you have a really bold paint color, repaint it a neutral color.
6. Shampoo carpets and if carpets are worn out, replace them.
7. Replace outdated fixtures in kitchen and bathrooms, recaulk & reseal as needed.
8. Repair non working appliances and if appliances are old or look like they have seen better days, replace them.

Furthermore, additional improvements should be considered based on your neighborhood and the comparables.  You should also review above items after a tenant moves out and before putting your home on the market again for lease.