What I learned, through a pretty good teacher whom I was lucky enough to connect with by pure chance, is to rethink how I perceived key signatures, and how I approached and saw many things. I had first studied keys as music theory, and had this "stuff" memorized which I had to "recall" in a little chant, like "F#, C#, G#, D#, A#, find those black keys, program my brain into them, and then start to play while hearing a B major scale in my head. Things of that nature.
I've been learning different approaches and mixing & matching things. For example, these three major keys all have the same thing in common: B, Db (or C#), Gb (or F#) major. They use all 5 black keys plus two whites - always one of the whites that touch each other (B,C and E,F possibly with their enharmonic spellings - C# major will have a B#, which is still the same white key as the C of Db major). Typically your thumbs will always go on the white keys, so in those two places, and the thumbs of both hands will do this at the same time. You can also create a visual "map" by mashing down all the keys that will be played for that key signature. .......... In contrast, for a C major scale you could cross your thumb at any wrong point because there are no black keys making it a Captain Obvious of choices, as with those three.
Thus, the "scary looking keys with those many sharps or flats" actually become the easiest, if you view it way different.
Chords is another. In major triads you have your whites (C, G, F), Oreos (bl wh bl) Db, Eb, Ab, Reverse Oreos (D, E, A), one all-black (F# = Gb) and "two odds" (B and Bb which reverse bl wh wh or wh bl bl). From there you can get minors by toggling the middle note (move one to the left), augmented by shifting either the top or bottom note from major, or dim7 by lowering a note from the minor and adding another m3. This gives you another perspective.
Finally; I learned to play the diatonic seven chords of all 12 major keys (so I(maj7), iim7, iiim7, IV(maj7), V7, vi7, vii "half dim" (I hope I haven't misnamed any), but NOT through any learned theory, memorizing anything, or anything that is intellectual. Instead it was by having this map of black and white keys in my mind's eye, and simply skipping over every 2nd note like a game of hopscotch. I had, at one time, done all this as music theory, intellectually. It was hard work. This was literally child's play. Later I did the same along a common sequence going along these degrees: 1, 3, 6, 2, 5, 1 (then added 4, 1 to cover all chords). This made the major keys more solid.
I had never thought of seeing keys (as in major/minor) this way, from that angle.
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With minor you have the problem of choice of scales: harmonic, melodic, etc. Either you go the "relative minor" route -- from C major to Am and start "raising" degrees 6 & 7 (the 6th and 7th note in your map); or you start with the major, lower the 3rd (giving you what we learn as "ascending melodic minor") and then lowering 6&7. This can also be a very physical-visual thing, rather than always going at it intellectually. We sort of want to merge the intellectual and the written theoretical. We don't want to always be "racking our brains to remember" memorized stuff.
Anyway, that's the change I've been going through for some time. That and other things.
Topic: Playing pieces in an easier key