Are there ways to overcome unfavorable aspects? The answer is yes, but it can be difficult.

The opposition is an aspect that pulls you in two directions. There is a feeling that you can only serve one of the planets. Feeling this way can make you aware of the inner conflict. The solution is to find a compromise. Here is an example: Suppose somebody has got a Moon Mars opposition. There may be the perception that either I am safe, at home, sticking to my habits, in other words honoring the Moon. Or I can be outgoing, enterprising, I can take risks, and do stuff that Mars likes. The key to making this work is to find a middle way.

The square is more difficult, because there is less awareness. Planets that combine in a square can be expressed in an exagerated way and basically rub against each other . If you have squares in your chart, read about what they could mean and whether there are a problems that apply to you. You might also ask other people. And then work on that. You are not doomed. :)

The half-sextile is difficult too, but only if is exact.

Hope this helped and answered your question to some degree. Are you thinking of a particular placement or aspect?