You must effectively waive your right to counsel
The Sixth Amendment to the Constitution of the United States and Section 10, Article I of the Constitution of Ohio give criminal defendants the right to counsel in most situations in the trial court. And it is not easy to waive your right to an attorney. Apparently, properly accepting a waiver of counsel is not easy for trial judges because a significant number of convictions are reversed on appeal because trial judges allow defendants to proceed without a lawyer even without an adequate waiver.
The case of State v. Brock, 2009-Ohio-6182, is the most recent example. The Licking County man showed up to his trial without a lawyer. The trial judge basically asked him if Brock wanted to proceed without a lawyer and Brock said, "yes, sir."
Of course that does not amount to an adequate waiver of counsel. Check out the Licking County Court of Appeals decision by clicking here if you want to see what the trial judge should have done.