Editing Warhammer 40,000/8th Edition Tactics/Space Marines (section)

====Command Points and You====
If you are gonna go for an all-marine army with CPs, it's gonna be hard to balance multi purpose, jack-of-all-whatchamacallsits with specialized elites, HS, Fast attack and HQs in brigades and battalions. Dodging the Troop Tax is viable with the Outrider, Spearhead and Vanguard detachments, but doesn't give as many command points, and CPs are like Psykers, they may do a little, or they may wreck your shit, and it's good to have a few just in case.
*You can build a Space Marine Army around 6 troop choices and burning Command Points. You'd likely need to go cheap on Fast Attack units. In this approach every turn you should use Hellfire Shells, Flakk Missiles and Expert Marksmen. If your model dies, but gets one last shot off with an Ancient, use the Flakk Missile and Hellfire stratagem for Mortal Wounds in your opponent's turn. Use Scouts to control how your enemy deep strikes, and use Tacticals to zone off your Deployment Zone. With a large pool of Devastators in your Deployment zone rerolling because of Lieutenants and Captains, when the onrushing hordes reach your army use characters to defend them, and use Honor The Chapter for a game winning Counter Charge by your heroic character. Use the Standard of Emperor Ascendant to maximize this shooting.  Because this build takes up  a lot of points and few/no vehicles consider using Assault Weapons on your Tactical Marines so they can Advance every turn. If you prefer this playstyle you should really consider allying with some Imperial Guard/Admech since they provide CPs and infantry screens for far cheaper.
**As hinted at above, allying with Guard/Admech for CPs is significantly less viable than it once was, with marines losing many of their faction specific rules if they soup another faction in. Also, with all the buff they've received, marines can make a low CP list work much more easily than they once could, to the point where its just not worth it to lose combat doctrines to get allies and CPs. 

**If you're struggling with CP and you would (obviously) rather stay with a pure Marine army, consider trying Ultramarines; two of their best characters grant free CP just by being the Warlord, and one of their unique WTs offers them a way to recycle CPs.