I liked Fralex's idea of a non spell-casting style of psionics and my first thought was to use the old Psychic combat attack and defense modes as the base of a monk style class.
For example at 1st level you would get your basic attack modes such as Ego Whip (melee range) and Mind Thrust...
I ran a campaign earlier this year that was based on Pathfinder/3.5 and I decided to convert some of the resources that I put together for that campaign into a 5th edition style for when I revisit the setting.
That setting previously included potent ritual magic that was essentially modified...