While working on a Flow/Neos proeject locally you must be finding it very slow and taking time to render pages. Why this happens is Flow keeps monitoring changes of files in ALL packages.
While we work on the project we really don't modify any other packages except the project packages. So what you can do is freeze all packages which you don't modify all the time. Mainly these include Packages/Framework/* and Packages/Libraries/*. So when package is frozen Flow does not look for file changes in it.
How to do on command line?
1. First freeze all packages
./flow package:freeze all
2. Then unfreeze packages you work on
./flow package:unfeeze MyProject.MyPackage
If you are using Neos then you can login to backend, goto Administration -> Package management then do above steps using UI
1. Select all and click Freeze
2. select proejct package and Unfreeze
./flow package:unfreeze --package-key MyProject.MyPackage
Confirm with ./flow package:list what packages are frozen and what now. * are frozen.