In particular, I wouldn't use mercurial without a .hgrc like this:
[ui]
editor = emacs -nw
[extensions]
color =
pager =
record =
graphlog =
purge =
progress =
transplant =
[pager]
pager = LESS='FSRX' less
attend = annotate, cat, diff, export, glog, log, qdiff, heads
histedit and rebase are also useful but not for my usual workflows.