For the development of samatha one has to apply oneself to a suitable subject of meditation. There are forty meditation subjects which can condition calm and they are the following:
10 kasina exercises, which are, for example, coloured
disks, a piece of earth, light.
10 loathsome subjects, (in Pāli: asubha), the 'cemetery
10 recollections, comprising the recollection of the Buddha, the
Dhamma, the Sangha, virtue, generosity, deities, and also the
recollections which are: mindfulness of death, mindfulness of the body,
mindfulness of breathing and the recollection of peace (nibbāna).
The perception of repulsiveness in nutriment.
The definition of the four elements (earth, water, fire and wind).
4 brahma-vihāras (divine abidings) comprising: lovingkindness
(mettā), compassion (karunā), altruistic joy (muditā) and equanimity
(upekkhā) which, in this case, is not upekkhā vedans or neutral feeling, but
the wholesome cetasika which is tatramajjhattatā.
4 meditation subjects for the development of the arūpa-jhānas
(immaterial jhānas), which will be mentioned later on.
Not all subjects are suitable for everybody, it depends on the individual which
subject is a means for him to become calm. If there is right understanding of
the way to become calm by means of a suitable meditation subject calm can
grow, even in our daily life. Mettā and karunā, for instance, can and should be
developed in our daily life, when we are in the company of other people and
then there are kusala cittas instead of akusala cittas. Recollection on the
Dhamma includes also reflection on the teachings and this is beneficial for
everybody; it helps one to begin to understand one's life. While we reflect
with kusala citta on the teachings or on one of the other meditation subjects,
there are moments of calm if we do not cling to calm.