user17246: I'm working on this video, football theme. i was wondering how I can give the ball a simulation of a comet or a cannon ball? 
For example when a player makes a strong shot i want it to look as if it was shot from a cannon or sth with fire effects. is there a tutorial for this?
Appreciate your help! Thank you

user17133: You might want to check out a class of effects known as "particle generators."
Trapcode Particular is a nice 3rd party option, but costs a bit of money.
AE has some built-in particle generator effects, too. Check out CC Particle World, CC Particle Systems II, and Particle Playground.
This tutorial here covers using CC Particle World to create fire. You could adapt that example to make a fireball instead of a wall of fire.
Particle Generator effects often have an source position property that you would need to match to the position of the football. This could be done with motion tracking, or simply keyframe it 'by hand' if the ball throw segment is fast enough.
Note that CC Particle World and CC Particle Systems II are very similar, but the first is a 3D effect while the second is a 2D effect. For shots where the ball goes from closeup to far away, the 3D variant would be helpful, but otherwise you might be able to get away with the simpler 2D variant.

user18382: I know this question is a little old, but someone else might stumble across it.
I have had great success using the VideoCopilot Saber Plugin for all kinds of effects including fire and fireballs. It's free and there are some great tutorials to get you started.

17246: <p>I'm working on this video, football theme. i was wondering how I can give the ball a simulation of a comet or a cannon ball? </p>

<p>For example when a player makes a strong shot i want it to look as if it was shot from a cannon or sth with fire effects. is there a tutorial for this?</p>

<p>Appreciate your help! Thank you</p>
 17133: <p>You might want to check out a class of effects known as "particle generators."</p>

<p><strong>Trapcode Particular</strong> is a nice 3rd party option, but costs a bit of money.</p>

<p>AE has some built-in particle generator effects, too. Check out <strong>CC Particle World</strong>, <strong>CC Particle Systems II</strong>, and <strong>Particle Playground</strong>.</p>

<p><a href="https://cgi.tutsplus.com/tutorials/create-fairly-realistic-fire-using-cc-particle-world--ae-2087" rel="nofollow noreferrer">This tutorial here</a> covers using <strong>CC Particle World</strong> to create fire. You could adapt that example to make a fireball instead of a wall of fire.</p>

<p>Particle Generator effects often have an source position property that you would need to match to the position of the football. This could be done with motion tracking, or simply keyframe it 'by hand' if the ball throw segment is fast enough.</p>

<p>Note that <strong>CC Particle World</strong> and <strong>CC Particle Systems II</strong> are very similar, but the first is a <strong>3D</strong> effect while the second is a <strong>2D</strong> effect. For shots where the ball goes from closeup to far away, the 3D variant would be helpful, but otherwise you might be able to get away with the simpler 2D variant.</p>
 18382: <p>I know this question is a little old, but someone else might stumble across it.</p>

<p>I have had great success using the <a href="https://www.videocopilot.net/blog/2016/03/new-plug-in-saber-now-available-100-free/" rel="nofollow noreferrer">VideoCopilot Saber Plugin</a> for all kinds of effects including fire and fireballs. It's free and there are some great tutorials to get you started.</p>
