First of all, start here.
https://www.coh2.org/replay
Upload a replay and ask for someone to review it on the strategy section.
https://www.coh2.org/forum/2/state-office
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What is your ranking? Against who you are struggling to win? Faction?
It's harder to give specific advise without knowing what you are having a hard time with.
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Do you have the means to record your gameplay? This is something that will be missed by watching only a replay.
This is more likely a general advice for playing RTS in general. Be intelligent with your current APM (action per minutes). There are a lot of low ranked players who have high APM but waste their actions by overcommitting to a single unit, fight or even moving units from place to place.
Minimap/Tactical map is your friend. IF you want to use the tact map, i suggest rebinding the numbpad 0 button to a mouse button or other key which is more accessible.
If you are not used to constantly check the minimap or you sometimes get too absorbed in the action which hinders your multitasking, open up any site with a chronometer.
Example:
https://www.youtube.com/watch?v=LaUe-Hf0uSM
Every time you hear the sound, check the minimap/tactical map/unit shield on top right.
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Use hotkey and control groups. Download any custom hotkey program such as autohotkey (ask here how to set it up).
It's a matter of preference, but using the gridkey layout on the menu results in an easier way to memorise certain abilities such as snares or grenades.
On control groups, this is really subjective on how to use it. For example this is my personal layout.
1-3: key units. In early game it might be an MG, sniper, light vehicle, pak. As the game transitions, so as well the importance of a unit. The MG control group transform in your tanks for example.
4-5: support units. Indirect fire units and engineers.
6-8: Howitzer/Rocket arty. Engineers. AA units. Any type of unit which doesn't require "finesse and fast" reaction as it's farther away from the natural position of the hand.
Just like when you learn how to type with a keyboard, start slow with a reduce number of hotkeys and slowly start adding them. Make yourself a personal patron which you can follow as to reduce any kind of mental effort input. You achieve RTS nirvana when you don't need to think of menial tasks which leave you space for you to think in the actual game at your hands.
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https://www.coh2.org/topic/18454/celo-company-of-elo
Be real and know that sometimes you face way better players that your currently self can't defeat. Use those matches to focus on smaller things in order to improve. Set smaller goals such as "let's not get units wiped in the first minutes of the game" or try to not lose as hard by getting your whole army annihilated. In a normal game, you need 2 VPs to win. Forget about it and try to focus on a more "defensive 1 VP" strat. Harassing other point and VPs is fine as long as you don't waste too much resources on it.