World conqueror 3 best conquest tips

Best tip for any conquest is make sure you have an city with an airport near by, that is how I capture 88% of the cities

What year have you played? I know that 1939 works for autoconquest

1939 Spain is currently the most recommended. Never tried by the way, so I cannot say it is a 100% succees though.

1943 India works as well

I just turned on auto battle 1st turn. May or may not end up working, It worked once and failed once. 

So, I've played this game for a while, I'm HQ 54, and I just completed my first alien conquest with Germany. I have a few tips for those who are struggling: Field Artillery spam in the beginning: Works with any country, enemies can rarely hit back and it does so much damage. This is a must. If it's WWII (1939 or 1943), don't bother with spamming tanks, as that only really works with Russia or Germany. Spam field artillery in Europe and Asia as the cities are clustered, DO NOT attempt to shift all your veteran artillery from one side of the world to another, it takes too long. Japan always falls under an invasion of artillery, as does the rest of the world. Also, paraspam your way into Asia if you're coming from Europe, it works really well (ask the Japanese or PRC or Russians or Germans) and take an industry level 2 city. Don't bother with bombing cities that are close and have good air defence like Nanking or Shanghai, just bombard them with field artillery. Also, I cannot stress this enough: take the initiative and attack from the get-go. Strike while the enemy is still mustering their forces, hit them with the blitzkreig, even the mighty USSR will fall. Do not wait for them to come to you, bring the fight to them before they can get rich and use their airforce to make life miserable. 

Cold War: Field artillery in the beginning untill you are able to hold the cities close to the front lines. Make sure you take whatever city possible, prioritizing those with an airport and industry 2+. After you push the enemy back, you can spam supertanks or paratroopers to go and attack Asia. If you're attacking from Asia into Europe, make sure to take and hold a city with industry 2+ and spam field artillery. To attack into China, paraspam from Moscow and Yektarinberg (1960) and focus on killing Chongking. Send supertanks to support your infantry as China'll paraspam you back. If you're WTO, paraspam and steal Chinese cities under attack from the US/Canada. Then, just spam field artillery/super heavies and finish them off. Use airforce and nukes to finish them quickly. 

Also, for both senarios, if you're the US, it's not that hard. Send troops to attack in both directions, prioritizing Asia and Africa, as those are the weaker allies. Send field artillery from Manilla to China/Japan depending on the war, and take the cities with industry 2+ and paraspam. Do the same thing in Europe, and make sure you get a decent foothold and can produce lots of field artillery. Once you get enough money, use your airforce to finish them off.

Aliens: Field artillery and rocket artillery to cross Russia. Strategic bomb the Tesla Coil thing, or nuke it twice. Don't panic if you get rushed, just build tons of field artillery and hold your cities, it's okay if one of them falls. Once you kill the rush, retake the city. Field artillery is your friend, spam it, you'll never have enough. To start, push towards the closest cities with good industry untill you can make 2-3 field artilleries a round. 

In short: field artillery spam and paraspam to get places far away, it works great and even works fine without good generals. For example, I can beat any conquest (except alien) as a 2+ star country in under 55 turns, 30 if it's the UK. 1 star countries take around 55-65 turns for me using my strategy. 

PS: Navy is not necessary for most conquests, it just speeds it up or does extra damage to high health generals/cities. Use a few battleships to take LA in 1960, or use a few carriers to attack enemy generals. Do not build fortifications, you are attacking, not hunkering down to hold the line. Field artillery is like a moblie land fort/ coast artillery with a ton more damgae. Armoured cars and super heavies are good agaisnt paraspam and so is field artillery. Sorry about the long answer, but this is how you succeed at WC3