How to Reduce High CPU Usage for WordPress on Shared Hosting?

How do I reduce the high CPU and memory usage for my WordPress blog in a shared hosting environment? My website http://livelifehappy.com receives over a hundred thousand hits a month which shouldn’t be a problem on a shared pro plan. My hosting company advised that it’s probably the Random Post plugin that’s causing the major spikes and crashing their servers. They’ve warned me several times. Does anyone know of any methods / strategies / tips that I can use IMMEDIATELY to reduce / lower the CPU usage so my host doesn’t freeze my account. Any help would be appreciated