Here a few tips
1. Do not use heavy tanks in 100 pt. games. If you use a unit like an IS-2 which costs 68 points you will have very little support units left. As soon as you lose the big tank you have almost nothing left to win with. Instead of heavy tanks use several medium or light tanks. The Sherman, The Cromwell, The Rhino, The M24, The T34, The Churchill, and the KV-1 are good options for the Allies. As for the Axis use the Elite Panzer 4, SS Panzer 4, or even the regular Panzer 4. All will do well leaving enough for support units.
2. Paratroopers or Partisans. Use them to the max. For the Allies use the Screaming Eagle. These guys are hard to kill. Plus have good ant-infantry attacks. Combine this with the Screaming Eagle commander and you have an infantry killing machine. The Axis have the SNLF. Use them to in numbers to get to the objective and defend it. Use the Communist Partisans to give the enemy a pain in the neck. Use them in numbers to attack the enemy hard while other units come in and attack giving you a good flanking postion.
3. Control the skies. Now that Aircraft are here controling the skies is needed for victory. To counter aircraft use aircraft with anti-air. Allies should use the P-51. Axis should use the BF-109 to do this. Also these units can deal with infantry on the ground. If no aircraft are avalible use a Bofors 40mm or Flak 20mm to guard the skies or defeat enemy infantry. Some aircraft like the I-10 or Stuka can be used as ground attack aircraft to take out enemy vehicles. Use a spotter to make them better. The problem with the Stuka or Il-10 is that they can’t attack enemy aircraft that well. Do not use the Stuka if enemy airpower is present because its slow. The Il-10 is hard to kill because of Superior armor.