Eldritch Charge

The idea here is to add some additional risk/reward to Eldritch Blast to mix things up for Warlocks. Instead of casting Eldritch Blast each turn for two turns, for a total of 2d10 force damage per beam, you forego damage altogether for the first turn and put all your eggs into one basket for the next turn when you cast Eldritch Blast. You then deal 3d10 total damage on the second turn for a successful hit. 

The upside is that you get an extra 1d10 damage in the end, but the downside is that you might miss altogether, giving you absolutely no damage and two wasted turns. The increased risk/reward is what I think makes this spell fun and interesting. 

The 1d4 self-inflicted force damage is mostly for realism within the game world, and should be overcome easily by most warlocks.