Sign the dist as the last step before creating the archive. Take care not to modify/regenerate dist meta files or the manifest.

Error: Old SIGNATURE detected. Please inform the module author to regenerate SIGNATURE using Module::Signature version 0.82 or newer. gpg: Signature made Sat 05 Nov 2011 09:51:48 AM JST gpg: using DSA key 2C5302215F6ADD3A gpg: Can't check signature: No public key ==> BAD/TAMPERED signature detected! <==

Add a META.json to the distribution. Your buildtool should be able to autogenerate it.

Add 'use warnings' (or its equivalents) to all modules, or convince us that your favorite module is well-known enough and people can easily see the modules warn when something bad happens.

Error: App::MathImage, App::MathImage::Curses::Drawing, App::MathImage::Generator, App::MathImage::Gtk1::AboutDialog, App::MathImage::Gtk1::Drawing, App::MathImage::Gtk1::Ex::IdleHandler, App::MathImage::Gtk1::Ex::SignalIds, App::MathImage::Gtk1::Ex::SpinButtonBits, App::MathImage::Gtk1::Ex::Statusbar::MessageUntilKey, App::MathImage::Gtk1::Ex::Units, App::MathImage::Gtk1::Ex::WidgetBits, App::MathImage::Gtk1::Generator, App::MathImage::Image::Base::BMP, App::MathImage::Image::Base::Gtk::Gdk::Drawable, App::MathImage::Image::Base::Gtk::Gdk::Pixbuf, App::MathImage::Image::Base::Gtk::Gdk::Window, App::MathImage::Image::Base::LifeBitmap, App::MathImage::Image::Base::LifeRLE, App::MathImage::Image::Base::Other, App::MathImage::Image::Base::Wx::DC, App::MathImage::Image::Base::X::Drawable, App::MathImage::Image::Base::X::Pixmap, App::MathImage::NumSeq::Abundant, App::MathImage::NumSeq::ChampernowneBinary, App::MathImage::NumSeq::ChampernowneBinaryLsb, App::MathImage::NumSeq::CunninghamChain, App::MathImage::NumSeq::CunninghamPrimes, App::MathImage::NumSeq::Derived::Cumulative, App::MathImage::NumSeq::DigitCountHigh, App::MathImage::NumSeq::DigitCountLow, App::MathImage::NumSeq::GolayRudinShapiro, App::MathImage::NumSeq::HappySteps, App::MathImage::NumSeq::HofstadterDiff, App::MathImage::NumSeq::HypotCount, App::MathImage::NumSeq::Lines, App::MathImage::NumSeq::LinesLevel, App::MathImage::NumSeq::LinesTree, App::MathImage::NumSeq::Ln2Bits, App::MathImage::NumSeq::Loeschian, App::MathImage::NumSeq::Obstinate, App::MathImage::NumSeq::Padovan, App::MathImage::NumSeq::Perrin, App::MathImage::NumSeq::PiBits, App::MathImage::NumSeq::PlanePathDelta, App::MathImage::NumSeq::PlanePathN, App::MathImage::NumSeq::PlanePathTurn, App::MathImage::NumSeq::PrimeIndexCount, App::MathImage::NumSeq::PrimeIndexPrimes, App::MathImage::NumSeq::PrimeQuadraticEuler, App::MathImage::NumSeq::PrimeQuadraticHonaker, App::MathImage::NumSeq::PrimeQuadraticLegendre, App::MathImage::NumSeq::PythagoreanHypots, App::MathImage::NumSeq::ReRound, App::MathImage::NumSeq::RepdigitAny, App::MathImage::NumSeq::RepdigitBase, App::MathImage::NumSeq::ReplicateDigits, App::MathImage::NumSeq::Spectrum, App::MathImage::NumSeq::SumTwoSquares, App::MathImage::NumSeq::SumXsq3Ysq, App::MathImage::NumSeq::TotientStepsSum, App::MathImage::NumSeq::UlamSequence, App::MathImage::NumSeq::UndulatingNumbers, App::MathImage::Wx::Drawing, App::MathImage::Wx::Generator, App::MathImage::Wx::Main, App::MathImage::Wx::Params::Boolean, App::MathImage::Wx::Params::Enum, App::MathImage::Wx::Params::Filename, App::MathImage::Wx::Params::Float, App::MathImage::Wx::Params::Integer, App::MathImage::Wx::Params::String, App::MathImage::X11::Generator, App::MathImage::X11::Protocol::Async, App::MathImage::X11::Protocol::EventHandlerExtra, App::MathImage::X11::Protocol::EventMaskExtra, App::MathImage::X11::Protocol::Splash, Math::PlanePath::MathImageCCurve, Math::PlanePath::MathImageComplexPlus, Math::PlanePath::MathImageGrayCurve, Math::PlanePath::MathImageQuintetSide, Math::PlanePath::MathImageWunderlichCurve

Add all modules contained in this distribution to the META.yml field 'provides'. Module::Build or Dist::Zilla::Plugin::MetaProvides do this automatically for you.

Add a 'repository' resource to the META.yml via 'meta_add' accessor (for Module::Build) or META_ADD parameter (for ExtUtils::MakeMaker).

Add SECURITY(.pod|md). See Software::Security::Policy.

Add SECURITY(.pod|md) and add a contact address. See Software::Security::Policy.

Add CONTRIBUTING(.pod|md). See https://docs.github.com/en/communities/setting-up-your-project-for-healthy-contributions/setting-guidelines-for-repository-contributors.