  We both review and augment the lightcone conformal truncation (LCT) method.
LCT is a Hamiltonian truncation method for calculating dynamical quantities in
QFT in infinite volume. This document is a self-contained, pedagogical
introduction and "how-to" manual for LCT. We focus on 2D QFTs which have UV
descriptions as free CFTs containing scalars, fermions, and gauge fields,
providing a rich starting arena for LCT applications. Along our way, we develop
several new techniques and innovations that greatly enhance the efficiency and
applicability of LCT. These include the development of CFT radial quantization
methods for computing Hamiltonian matrix elements and a new SUSY-inspired way
of avoiding state-dependent counterterms and maintaining chiral symmetry. We
walk readers through the construction of their own basic LCT code, sufficient
for small truncation cutoffs. We also provide a more sophisticated and
comprehensive set of Mathematica packages and demonstrations that can be used
to study a variety of 2D models. We guide the reader through these packages
with several examples and illustrate how to obtain QFT observables, such as
spectral densities and the Zamolodchikov $C$-function. Specific models
considered are finite $N_c$ QCD, scalar $\phi^4$ theory, and Yukawa theory.
