I am writing the first part of an invention. I wrote it to the first cadence (C Major) but realized I did not create an episode with sequences. I am a little stuck on how I would go about doing that. Where should the sequences start? What exactly in my piece is the basis for my sequences? I appreciate any feedback.
What is written so far is a single phrase comprising your subject, played in canon, and ending on a cadence in C. Start your sequence right there.
As an example, consider Bach's Invention #1:
In measures 1 and 2 Bach lays out the primary theme, and cadences in C major on the downbeat of measure 3. He then immediately takes off on a sequence.
In your piece, there are frequent three-note scalar passages, and they would make an excellent basis for a sequence. For example, starting from where you've ended:
X: 1 T: Sequence example M: 6/8 L: 1/8 K: F %%score V1 | V2 [V:V1] c'ba b3/2c'/2b | agf g3/2f/2g | fed e3/2f/2e | [V:V2 clef=bass] C3 G,3 | A,3 E,3 | F,3 C,3 |