Lots of this is very house specific but I'll take a stab at. In Scripps Ranch I often find buyers can fit in 1 of 3 categories. 1- the polish 2-just get in 3-redo-ers.
1-The polish. These are typically those paying top dollar and they know it. But in return the expect everything to be polished, and if it's not they intend to redo anything outdated prior to moving in. If it's not turn key, these people typically see improvements as an interferance to their already busy lives. If this is your property target, polish, primp, repace carpet, change countertops and definately have a professional stager (interior designer) go through the property and de-clutter. Greatest value is paid by these people when it is all done already. Generally if you can't do it all, many of these people will pass on your property.
2-Just get in. These are the people who intend to do renovation, but getting into their neighborhood of choice at a reasonable price is more important. They will take the next 5-7 years to make their desired improvements and are able to look past some unpolised things. In this case, generally a liviable home with the needed square footage is typically best. Best improvements here often are adding a bedroom, or just replacing carpet for the sale. Fressh coat of paint in and out and again stage it professionally.
3-re-doers. These people largely want to do their own work. No improvements are necessary as they will likely re-do anything you chose to have done to the property anyhow.
So, in summary, if you are planning too sell your home real soon...carpet, professional staging, fresh paint. If your home is close to being completely polished already, finish the job and you will get top dollar. Have someone honest walk through your home for you. don't be the judge yourself. You are biased and like your taste.
If you are not close to selling your home, improve things you will enjoy while you are there, then move onto those other items when it is time to sell. Likely your improvements may need cleanup or renovation again at the time of sale anyhow. Do it for you, enjoy your home...worry about the sale, when you sell.
Or, lastly I'm happy to swing by and give a more personlized assessment whether you intend to sell or not. Never any obligation. And, I am happy to share some well credentialled contractors.