I don't enjoy slim fingers nor an ectomorphic body tending to flexibility and length. Here are some of my observations. Keep your nails trimmed short for a start. Fretting, fleshy tips compress in comparison to boney. When they do, if your nails aren't short, the nail will strike the fingerboard so the string isn't fretted well and its note may not ring true. This may also incite beginners to use excessive pressure fretting which in turn slows you down which coincidentially may increase any perceived pain or tip soreness associated with the activity when new.

Greater attention to form is required. In particular, perpedicularity of fingers to the strings so they don't foul adjacent strings unless intentionally muting or irrelevant. This also translates to greater diligence with arm and palm positioning, thumb placement for optimal facilitation of -usually, shorter fingers with shorter less flexilble intervals between joints. All goes with the genetic build. Short of a potential bionic hand transplant sometime post circa 2400AD, the general rule currently is observe, recognise, adapt.

Flexibility exercises. Although more challenging for those who aren't endowed with that characteristic genetically, they become even more important. And of course, the obvious, if 'sausage fingers' are compounded by obesity or disease associated fluid retention, lose the fat or see a doc about the latter.

Lastly, equipment. All guitars aren't equal. Choose a guitar with string spacing, neck profile, scale length and of a size which advantages rather than disadvantages characteristics of your individual build.