This was developed weeks ago and we found it very helpful when we came back to Lost Battles after a while having played other games.
I decided to share it.
Feel free to download the attached file.
The Combat-Modifier-Markers allow you to pick up only combat-modifiers for the battle you just want to play.
So, for example, at Marathon there are no chariots, no elephants, no light infantry, no light cavalry, no phalanx, there is no wet weather and there are no streams, no rivers, no woods, no marshes - hence, you do not need combat modifiers for this.
As a result of that you can play that battle with a handful of markers which will represent the modifiers and you have the advantage to put the valid ones beside the attacking unit (even good if you play solo) to show your decision.
You can see at a glance the result using the bonus-malus-system.(see images 1155909,1155908,1155907)
To have good results in making the markers, print on photo-paper and laminate with Laminating pouches 125 micron.
Do yourself a favor and round/chamfer the corners.