Instead of making a value judgment about yourself:

I am organized and detail-oriented, as well as motivated and dependable under pressure.

Attribute to professors or former employers:

My professors can attest that I am organized and detail-oriented, as well as motivated and dependable under pressure.

Instead of making a value judgment about yourself:

I can handle major responsibility and I adapt well to change.

Attribute to professors or former employers:

Previous employers will affirm that they have entrusted me with major responsibility and that I adapt well to change.