  We consider multiskyrmion configurations in 2D ferromagnets with
Dzyaloshinskii-Moriya (DM) interaction and the magnetic field, using the
stereographic projection method. In the absence of DM interaction, $D$, and the
field, $B$, the skyrmions do not interact and the exact multiskyrmion solution
is a sum of individual projections. In certain range of $B, D\neq0$, skyrmions
become stable and form a hexagonal lattice. The shape of one skyrmion on the
plane is fully determined by $D$ and $B$. We describe multiskyrmion
configurations by simple sums of individual skyrmion projections, of the same
shape and adjusted scale. This procedure reveals pairwise and triple
interactions between skyrmions, and the energy of proposed hexagonal structure
is found in a good agreement with previous studies. It allows an effective
theory of skyrmion structures in terms of variables, referring to individual
skyrmions, i.e., their position, size and phase, elliptic distortions etc.
