Webel: SysML: DO NOT sacrifice modelling naming conventions for the mere sake of carrying organisation-specific names! Instead use tagged values of custom stereotypes as metadata to carry alternative names in parallel with systematic model element names.
SysML/SysPhS-1.1: Anonymous Property or Action names may not be an option if: You are exporting to Modelica or Simulink; You absolutely need names for generated query reports (such as generated Interface Control Documents).
Webel: In some SysML trails ValueType names with Unit indicator suffixes have been used for dimensional analysis and illustrative purposes. This practice is otherwise NOT recommended here. Instead just use consistent custom ValueTypes across your system!
SysML: When using Property::defaultValue and Property::redefinedValue to carry a "shadow hierarchy" of redefinitions across an entire system hierarchy, considering using a user-defined keyword such as «configuration» or «scenario» on each redefining Block
UML/SysML: Navigation: Try to offer a way out of a diagram (usually up a hierarchy, but possibly across) using a navigable symbol (linked to a diagram) and/or a diagram symbol. Avoid "cul-de-sacs"!
Block naming: If you find you've got similar blocks named 'Thing' and 'Thing2' then 'Thing' is probably better renamed 'Thing1'
The use of an additional «port» keyword on a Port is usually redundant and causes clutter. The use of an additional «port» keyword on a basic Property is an obsolete trick. Please don't imitate it even if you see it in some specification sample diagrams!
Webel Best Practice: SysML/SysPhS: DO NOT use overlapping Connector lines from/to one Port (can be misunderstood as "summed" flow and/or physical node/fork/junction).
UML/SysML: A Boolean "state flag" attribute corresponding to a State can be useful for indicating states in some diagram types (but must be synchronised with Transitions to States carefully).
UML/SysML: During modelling it can really help to create little instance (object) diagrams as you go! This can also help communicate with non-SysML stakeholders.