Each upgrade should have a reason.
If your bushing is sloppy, fit a new one or tighten up the old one.
If your extractor doesn't extract well, fit a spring steel extractor, and
polish it for reliability. If you carry your 1911 for protection, do the same.
If you have problems reaching the mag release or hitting it when you want, fit an extended release.
If your gun is unreliable, send it to a well known 1911 gunsmith such as Clark Custom for a reliability package.
If you have an accuracy problem, let a seasoned 1911 shooter shoot your gun. If he also has an accuracy problem, send the gun in for an accuracy package. If the seasoned shooter outshoots you, invest in competent instruction rather than parts. Most 1911s will outshoot most shooters.
IMHO the best things to buy for most 1911s is ammunition, spare magazines, a holster and instruction.
Modifications for upgrades sake is a waste of money. Modifications to allow you to shoot more accurately and get hits on target faster are what customizing a 1911 to your own personal needs is all about. Until you shoot the gun a while, you will not know what you want or need. After you shoot the gun a while, you will not feel the need to ask which upgrades are best on an internet forum. You will already know which ones are best for you. The gun will tell you.