In English writing, often خ becomes "kh" and the others are combined into "h". For example, محمد → Muhammad (with "h" meaning ح), الله → Allah (with "h" meaning ه).
In lossless Arabic transcription, ح is usually written "ħ" (h with bar) or "ḥ" (h with under-dot) to separate it from ه. But this is rare except in textbooks and scholarly works; I've never seen a news article refer to *Muħammad or *Muḥammad.
Lossless transcription also needs to distinguish "kh" خ from "kh" كه . One approach is to spell كه as "k'h" (ALA-LC does this); another is to write خ as "x" (per ISO 233-2) or "ḫ" (h with under-breve). I personally prefer the second of these options. A handwritten apostrophe is too close to the symbols for ayn and hamza (ʿ and ʾ), while ḫ and ḥ tend to look very similar in print; writing the three as "h", "x", and "ħ" makes them much easier to tell apart.
(In lossy transcription, of course, the distinction between the "kh"s can be ignored entirely.)