Don't be gentle to your firearm
Many beginner firearm users experience some problems while handling a handgun. Here we will tackle two most widespread problems related to chambering. And we are going to kill two birds with one stone: one advice - both problem solved.
First, let's describe the problems. And we assume that the gun is properly serviced and has no mechanical malfunctions.
Problem #1: You try to chamber your handgun and it results in a cartridge jam.
Problem #2: You try to chamber your handgun and nothing happens - you are pulling a trigger and then find out it is not chambered.
To cure both problems I suggest to follow an advice I got from a military instructor: "Don't be gentle to your firearm!" Let's see into the matter, i.e. what it means in practice.
With a probability of 99% you get Problem #1 because you don't release slide right away while chambering. To chamber properly you should pull the slide all way back and release. Trying to do it gently, and follow the slide, assisting the spring, will result in cartridge jam. It is because the spring should do the job at certain speed. So, never assist the spring to do its job, be like a cool hero of an action movie: pull the slide back and release. Enjoy metallic clang and you will never have to pry out a jammed cartridge (unless, of course, you inappropriately modified your firearm or by accident you blocked the ejection port with your hand while doing it)!
Problem #2 happens rarely, but may puzzle you even more than the first one. The explanation is very simple: you didn't insert the magazine all the way up. So, when you pull the slide back and release, nothing happens, because it cannot catch the top cartridge to chamber it. And please, do not expect that the magazine will fall out - not necessarily, it may be still holding inside the grip, but inserted not enough to do its business! And the solution here is the same: don't be gentle - insert a magazine rudely till you hear the appropriate sound (click, clang, crunch - depending on your firearm and your musicality). Now it will work 100%. By the way, the same mistake (not inserting magazine up enough) may also result in a cartridge jam.
Both aforementioned problems are not big problems if it happens in a shooting range. God forbid, but sometimes they may cost your life! So, really, don't be too gentle to your firearm! This, as well as not using old, corroded and defective ammo, will secure you from 99.9% of all possible cartridge jams.