Ah yes, 'boy clothes' - I remember!
I didn't have much in the end. I had moved out of my parents' home shortly before my scheduled surgery and into an apartment in a different city and that was 'transition' for me. Since my legal papers were still "M" (and it was 1974 after all), I travelled to the U.S. for surgery in boy mode. I had the nicest Hispanic nurse and we became good friends so I gave her boyfriend the last of my male clothes while I was still in hospital.
Now I am usually fairly smart but there was one thing I had overlooked - getting back into Canada - but it never dawned on me until the last moment. I had a nice flight back to Toronto flirting with a young businessman on the plane and was just high on life until we were approaching Customs & Immigration and I realized all my official papers were male and I didn't look anything even remotely male. Oh oh!

Not knowing what else to do and not wanting any hassle from the Immigration people, I clung to the young man's arm as we went up to the Immigration officer. He asked the young man his citizenship, where he had been, and how long he had been gone. After the young man answered, he looked at me and I said "Same." and the officer waved us on. It worked! The officer assumed we were a couple and I was back home.
What a relief! I had visions of being hauled off to a back room and trying to explain why a young woman was travelling with male papers.