Use an IDE like DataGrip to test your SQL queries prior to running them in Mitto.
Write comments in your queries to document what a query is doing. Mitto only accepts multi-line comments. For example:
/* This is a comment. */ Select 1;
Including table schema
It is a good practice to fully qualify your tables by including the schema of the table.
For example if you want to mirror an entire table:
SELECT * FROM <schema>.<table>;