Make a new solid & a Null Object, keep the Null Object above the solidYou can rename the solid (its just to be organized)Add the effect "Optical Flares" on the solidDisplay the blending modes on the button below and select "Add"Select your clip and in the "workspace" bar at the top right corner click on "Motion Tracking"Then click on "Track Motion" with your clip selectedYou can now add the points that allow you to track your optical flare effect. Please choose a contrasted area and adjust the square to make your point fixedYou can use the button "Analyze Forward" that your tracking is done automatically. If your target is bad adjusted the point can move and it will cause you a bad trackingYou can also do it manually by going directly into the trackpoint list (Track Point 1). Each key on the track matches a point tracked at a specific time where the cross is placed (The cross at the middle of theses squares)With the manual method you will use the "Analyze 1frame forward" button this allow you to track frame by frame while replacing the cross where you want (remember : The cross is the middle point of your Optical Flares) So work your aim to center your flares correctly ;)In this example, I'm doing it automatically and the point deviates slightly because of the camera movement. You can go back and delete the wrong tracked points or replace them manually (yes it's very long;)Once you tracked your flares correctly. Click on the button "Apply" by targeting your Null Object. If you have only one Null Object it will be targeted automatically so just click "OK"Open your Null Object & your Solid. Search "Position" in "Transform" for the Null Object and "Effects" >> "Optical Flares">> "Position" for your flaresMaintain the "Alt" key and Left Click on the chronometer of "Position XY" it will open a red lineLeft Click on the spiral, maintain, and drag it on the "Position" Chronometer of your Null Object. Don't forget to get the chronometer of "Position" enabled on the Null object layer beforeRelease the link on "Position" and click in the void to deselect allNow your flares is well trackedGo the the "Optical Flares" options and choose the one that you like. Then you can edit the settings as you wantThere's the tracked points. More you add points, much longer your flares will be trackedIf you want your flares more bright sometimes, click on the chronometer of "Brightness" and "Scale" then add some keys on the moment that interest youEnjoy yourself and choose the settings that you like