Practice reading tenor clef by writing out familiar tunes in tenor clef. Play the tunes while “reading” the music, but using your ear to help you stay on track. You are working on developing the “hand/eye coordination” you need to read music in tenor clef without hesitation. Expect to start slowly, but be patient. Avoid shortcuts and gradually, especially if you intentionally read tenor clef every day, you’ll soon wonder what the “problem” was!?! Next, work on reading treble clef (you may like to transpose music in treble clef an octave lower to start). You want to read music in a variety of clefs as “automatically” as you read the bass clef!