I have went through several phases as a composer, each one lasting about a year:
Phase 1: Ambition
This first phase lasted about a year and most of my successful compositions were Piano Solo at the time, but I was trying everything I could think of. Symphonies, Fugues, Sonatas, Quartets, Trios, Canons, everything. My first symphony idea was in Phase 1. My first chamber works were in Phase 1. If I couldn't compose for a certain ensemble, like String Quartet for example(even 4 years later, I still have troubles with the String Quartet ensemble), I could sure arrange for said ensemble. In fact, most of my successes in Phase 1 were arrangements and not compositions. My pieces strongly emulated the greats, first Pachelbel, then Mozart, then Chopin, then Beethoven, then Bach. Beethoven and Mozart were the 2 that I emulated most often and are my 2 strongest influences, the 2 strongest roots of my compositional style, and my first and second favorite composers respectively. Later in this phase, my harmonic vocabulary expanded and it would just continue expanding.
Phase 2: Stability
This second phase was a point of stability for me, and it also lasted about a year. This is when Chamber Music became my most common ensemble, usually a Duet or Trio, occasionally a Quartet, more often a Quintet or larger than a Quartet(and if a Quartet, usually Woodwind Quartet). It is when I really started experimenting with pairing different instruments together, like Bassoon and Cello for example. It is when I really fell in love with the Suite as a genre, although my first and still incomplete suite has roots in Phase 1. Without knowing it at first, I was destined to become one with the orchestra, to write orchestral works more often. That's right, my first orchestral work ever, Viaggio de Mare originates in Phase 2. It is also when I noticed that Programmatic Music was way easier for me to compose than Absolute Music. Even Sonatas were easier to compose if I had some kind of atmosphere as a reference. I still compose some Absolute Music to this day, but most of mine is Programmatic. The form started to subconsciously unfold itself instead of me forcing it in. It's when I knew that Sonata Form and Rondo Form were to be my 2 most common forms, even outside of Sonatas. But then, suddenly, it was like a spark lit up in me last summer.
Phase 3: Confidence
When I composed that March of Iwo Jima piece and finished it, I knew, I just knew that the orchestra was finally in my grasp, and I started writing quite a few more orchestral pieces. I was very close to the Symphony and the Concerto being in my grasp, but I wasn't quite that confident yet. The orchestral suite though? No problem. Programmatic pieces for orchestra? No problem. Recomposing an earlier chamber work for orchestra? No problem. So what if it takes me a long time to compose an orchestral piece? It would take me a very similar length of time for a Piano Solo composition as it would for an orchestral composition. The important thing here is that I gained enough confidence to compose for the orchestra without it overwhelming me(which is what it did when I was composing Viaggio de Mare and is why I only have 12 measures of it written down). I of course still compose chamber works and relatively recently there has been a resurgence of Piano Solo with my 25 Preludes, but the orchestra will always be one of my go tos for composing.