carefully, with care
A label on the crate read: ‘Handle with care’.

carelessly
Gardening tools can be hazardous if carelessly handled.

roughly
Many of the prisoners were roughly handled; some were killed.

competently, efficiently, properly, skilfully/skillfully, successfully, well
I think you handled that situation very well.

badly
carefully, delicately
This issue may need to be handled carefully.

easily
Her next question was not so easily handled.

routinely
The library routinely handles a wide variety of queries.

be able to, be unable to, can, know how to
This was a problem that I just couldn't handle.
She knew how to handle publicity.

be designed to, be equipped to
He wasn't mentally equipped to handle this situation.

learn how to
be easy to
be difficult to, be hard to
Large meetings are more difficult to handle.

with
She handled the crisis with total assurance.

Handle is used with these nouns as the subject:
bureau

Handle is used with these nouns as the object:
affair, ball, business, call, cargo, case, challenge, chore, complaint, complexity, conflict, correspondence, crisis, criticism, data, demand, detail, disagreement, disappointment, disaster, dispute, distribution, divorce, duty, economy, emergency, emotion, enquiry, finance, firearm, food, freight, gun, horse, incident, influx, job, liquor, load, mail, management, matter, negotiation, paperwork, pressure, problem, query, rejection, relationship, request, responsibility, rigour, role, situation, stress, task, text, thing, traffic, transaction, truth, waste, workload