-ようにする/ように心掛ける

The expression ように has different functions, and the
combination of ように+する carries the meaning of
'make it a habit to do such and such'.

Since ようにする expresses one's habitual action(s),
V-ている form (i.e., -ようにしている) is often used.

-ように心掛ける basically expresses the same meaning, but
it implies that the subject is 'making more effort(s)'.