The standard method is for Lara to be facing the corner of a column
while also standing at the edge of a ledge. Then Lara jump straigh up,
and the game prevents her from going off the ledge, but not from moving
into the column. If she's facing at the proper angle (about 30 to 45
degrees to the side), she'll go into the column while jumping, then
end up on top of the column on the next jump.
For TR3, Lara can also crawl towards the corner to do the same then.
Instead of jumping, press duck and tap forward, then release and repeat.