Let's assume you have the first turn. Let's also assume you are playing to control objectives. You will want to move your transports onto the objectives and pop smoke if necessary. Use terrain for cover and cut off enemy LOS. It's worth investing the points in dozer blades for your rhinos as they are dirt cheap and you will often need to move into difficult terrain for cover. Place your objectives such that they are close to your deployment zone and easy to reach with one move. By doing so you will force the IG to counter by moving their chimeras towards your line. This will bring them into range of your meltaguns so you can pop them. Keep your squads embarked for maximum protection as they are safest inside their rhinos during both the initial phase of the game (turns 1 & 2) and into the midgame (turn 3). You must also decide what are your first target priorities during the initial phase of the game. Vendettas are easy to target in the initial phase since they are mounted on high flight stands. I will generally target the Vendettas first since they typically don't have an intervening cover. Vendettas are fairly easy to drop with your lascannons and the CSM list I have presented has up to 8. Once you have eliminated the IG skimmers they can no longer snipe your armor. So the first two turns are all about taking objectives, using terrain for cover or blocking LOS and dropping the Vendettas.
The midgame is when you will want to eliminate the tanks (Leman Russes, Leman Russ variants, Medusas & Manticores). It's important to focus on destroying tanks that can drop one pieplate and wipe out a squad of Nurgle Marines. The main emphasis should be all about focused fire on Leman Russes, Leman Russ Demolishers and Leman Russ Executioners as this class of tank all have high strength low AP pieplates. The Demolishers in particular are extremely nasty as they can easily destroy both your armor and troops. Next up is the Executioner as it can drop up to 5 plasma small blast templates. The Executioner can easily wipe out one squad of exposed troops plus your lightly armored rhinos. You can shoot them with your plethora of lascannons plus by midgame your meltaguns should bs in range as well. If you can eliminate the bulk of the Vendettas plus the bulk of their ordnance then all you have left to target are chimeras. Even if you only manage to shake or stun a tank you have prevented it from shooting the next turn which is very helpful plus it can leave the enemy exposed. Remember that typically it's best up through the midgame to keep your troops embarked for safety; you can still move your rhinos up to 6" and still fire your meltaguns from the hatch. This is a conservative style of play and you are counting on your opponent to make some mistakes. Basically you should be in a position to control the most objectives forcing your opponent to react to your game plan.
To be continued...