I started with simple things...Rock star parking, calling the elevator, awesome tunes on the radio when i was taking a trip.
Practice self awareness so you aren't sending little barbs of fear with your intentions.
Abundance is a good one to manifest and a good example cuz everyone loves to have an ample supply of say..money. But don't manifest from a place of want..let go of the fear of not having enough money.. focus on what you do have...a warm place to sleep, food, water, air to breathe, love. See your blessings.
Once you call for it, stop thinking about it...know that it will manifest. If you continue to think about it, you are calling the energies back to you, mirroring the opposite.
It's real important not to focus energy at someone else's expense...that will back fire.. So, if someone cuts you off in traffic, don't wish them a HUGE pimple on their nose unless you want to stop and buy yourself some clearasil on the way home.