Shutter lag refers to the time duration between pressing the shutter button and the final recording of the image data. Most of the modern day cameras have an extremely low shutter lag time but the cheap cameras take a noticeable amount of time in capturing the image that varies from 1sec or more. However the high end cameras (canon 1DX and Nikon D4S) tend to have almost no shutter lag.
Whenever I prefer to use my cell phones camera, due to the notable shutter lag it becomes real hectic to capture scenes. Hence as per my personal experience I would suggest the cell phone manufacturing companies to design cameras with less shutter lag.
Most of the users of the point and shoot camera don’t allow their cameras to focus on the subject the lift the camera and immediately press the shutter button, so the camera takes noticeable time to focus on the subject after the shutter button being hit. But according to the rule, one must first firmly focus on the subject by pressing the capture button half-way and then click the image.
And once again as we always say- you must keep on practicing the tutorials and tips, to improve your skills.