Hello, in this tutorial I will explain you easy strategy for blitzkrieg as German Reich.
In the beginning we must build some military factories, and collect 50 political power for justify wargoal on Poland. German Reich have a lot of factories at start so it easy to collect weapons and train a lot of divisions before declaring the war against Poland.
We have 30 divisions, train 30 or more 20 stretch infantry with support equipment, a few armored division and motorized divisions. Collect Political Power to demagogue and collection law. It's important to produce a lot of submarines for naval invasion at Great Britain and planes to air domination. Research industry, military, land doctrine, engineering and set national focuses on industry (don't go to Rhineland at start - its important).
Send 24 divisions to Prussia, and rest to border with Poland. Allies won't join the war otherwise send 24 or little more infantry divisions on Maginot Line. Around 300 days after the start you can declare war against Poland. Set offensive line in the army in Prussia to Lwow, border army set to Warsaw. War with Poland will be quickly and easy.
Next stage is to conquer France. You will need wargoal on Belgium or Netherlands to get past the Maginot Line on north. Left some of infantry divisions on the north-east Germany (Great Britain will try to naval invasion in your territories). If you declare war on the France, Italy will want to join the Axis, so wait for French troops that were sent to the Maginot Line, and accept their request to join the faction. Later call Italy to the war, they will attack southern France. It will be easy to conquer the France, you will see.
Next we want to reach Great Britain so send 48 divisions to the naval base in Calais. Take 10 infantry divisions to the naval invasion order, and select province close to Dover(don't select naval base!). Wait for prepare the invasion. If it will be done, take all of your submarines to English Channel and take option named Patrol and all of your plane to air domination the channel and Southern England. If you will be ready, activate the plan. Wait for this 10 infantry divisions, and if they land on british coast, take naval base in Dover. Send rest of your division to this naval base (38 divisions), and you can easily conquer the all of britain quickly.
With this tutorial you can conquer Poland and Allies before 1940 (you can also receive two or three achievement at regular difficulty and ironman mod). Good luck and have fun!