Raising and lowering Kartoffel symbols and their covariant derivative forms make manipulating the coordinate transforms possible (4-6 dimensional)... otherwise it would just look like pages of equations.
Interestingly, mechanical engineering also deals almost entirely with tensors... and they've developed extremely intuitive visualization tools.
What visualisation tools are you referring to? That sounds interesting.
https://en.wikipedia.org/wiki/Cauchy_stress_tensor
Look at Mohr's circle:
https://en.wikipedia.org/wiki/Mohr%27s_circle
Within an object the stresses and strains (and principal components) vary as you move through it. That's part of what makes predicting failures and effects of thermal expansion so complex, etc difficult even ignoring nonlinear effects and failure modes (e.g. crack propagation).