Constant pH MD simulations have been performed with various electrostatic models, including generalized Born, 9 shifted cut-off, and Particle Mesh Ewald (PME). Of these methods, the Ewald summation based PME method is generally considered to provide the most accurate description of the electrostatic interactions in periodic biomolecular systems. Because Ewald summation can only provide accurate results if the simulation box remains neutral, the charge fluctuations associated with the dynamic protonation and deprotonation in constant pH MD simulations need to be compensated to prevent artifacts. Titratable sites can be directly coupled to special particles, modeled as ions or water molecules, such that charge is transferred directly between the titratable site and that particle. Alternatively, all sites can be coupled collectively to a sufficiently large number of buffer particles. The latter approach has the advantage that spontaneous fluctuations in the interaction of the buffer particles with their environment affect all titratable sites to the same extent. The disadvantage is that the setup and parameterization of the buffer approach are more involved, as it requires selecting the number of buffers and parameterizing their interaction with the rest of the system. To facilitate the use of buffers in constant pH MD, we provide a parameterization strategy aimed at preventing buffer clustering, buffer binding to titratable sites, and buffer permeation into hydrophobic regions. We demonstrate that buffers parameterized with this strategy also avoid finite-size effects associated with the periodicity of small simulation boxes.