1 - Always perform deferred maintenance or you will be inviting offers knocking off morethan it would cost in reality to bring up to standard. Perform the maintenance, i.e. replace garage door, update outdated kitchen appliances (if they are) and flooring, mid-to late century but original bath or kitchens: update as much as your neighborhood will let you get a return on your investment (do not over improve in a neighborhood that would warrant making your home the highest priced). And I shouldn't have to say it, but replace the worn toilet seats and throw out the dead house plants.
2 - My personal deferred maintenance of my home for 14 years near Annapolis, MD included a new dishwasher, roof, garage door, kitchen and hallway flooring, clean carpets, removal of wallpaper, touching up paint and pulling out all of the foundation plants in the front of the home and replacing them with pleasing but correct foundation plantings (the former owner thought planting forsythea across the front of a 30 x 8' front porch was appropriate - not! - plantings should differ in texture, size, but mature to so large that the house is overgrown in one season, let alone say, 10 years). We also power-washed the house, walk, drive & outdoor patio furniture and replaced the shutters, painting them & the new garage door to match. Additionally, I pre-packed non-essentials of our "stuff" that pegged a)our religion, b)collections of pottery and china, handmade items such as quilts (one might display their collections proudly - but remember you want the buyer to look at the house, not your collections because you will not be selling those). Additionally, coin & stamp & all valuable collections, and firearms need to go bye bye!!! Pack up all family photos, framed certificates from schools and professional accomplishments and even if with the president of the US (which we frequently found in the Annapolis area) pack them up. Storage lockers and moving PODS are not that expensive if you have things you wish to keep but will streamline your home to being sold.
THINGS THE BUYER SHOULD NOT BE ABLE TO TELL WHEN WALKING THROUGH YOUR HOME: your sex (if single add in some items of the opposite sex), if there is a divorce happening (uncared for house plants and homes are the usual tip-off), your ethnicity, who your family and friends are, which country club you belong, and if possible which age range you are.
(Children closing down parents' homes have a challenge: the home will be dated in all likelihood: if not in a high end neighborhood, remove paneling, wall to wall carpet, window treatments that block sunlight & replace flooring if it will bring a more appealing look. For my mother's 48 year residence coated in nicotine we removed all window, carpet & wallpaper; painted one wall of paneling to antique white which was also used on all the walls to seal in the nicotine stain and painted the long lived but wonderfully functioning Sears metal cabinets that mom had painted brown, to white. On the exterior, we hired someone to remove about 15' of vines and invasive plants that had grown around the perimeter of the back yard. It was unbelievable the amount of yard reclaimed to make it look like the largest lot in the neighborhood - which it was! Work was started in June but not finished until Sept 1, thus I bought planters and plants for front stoop and deck and maintained them the entire summer as no plants would have been available to dress up these areas. Some furniture which had not fit into my parents' apartment was left behind. Thus, we used it to stage where possible. The cost was $7500 for the deferred interior maintenance. Had this not been done it would have sold for $80,000. With the investment and a list price of $129,900 (it's absolute rock bottom selling price - others were listed ten & thirty thousand more), but as a Realtor [sorry, I didn't mention that before] I wanted competing buyers. The first day brought three contracts 1 to $3,000 over list price. You have no idea how far that equity contributed to my parents' quality of life. With no other bills, but medical challenges in the wind, I was able to capture some of the money that frankly not only paid for special extras for them, but even the flowers for their funerals. (Attorneys specializing in elders are worth their weight in gold).
3 - As a Realtor, I always advised updating kitchens, removing light stealing window "sheers" - upping the wattage in their lighting, skirting the tall trees with limbs lower than the roofline. (One would be surprised how much light is stolen by these large leaf laden limbs. Oh! Absolutely remove dead & or rotting trees including stumps and of course old stumps. Frequently I was met with resistance on staging, but buyers like to think one thing: this home was loved by the homeowners and its maintenance was always seen to promptyly, even if that floor with the gouges in it was only replaced the week before or the front door's paint was barely dry, it says "loved!" "maintained!"
A boss once told me if you see one cockroach in a house, what do you think: oh my, what else is looming in places I cannot see? You want the potential buyer to think, wow, it's so clean and well maintained. "I'm comfortable that there won't be any big surprises on down the road."