Mathematica: Webel: You CAN/MAY use $ in variable names and function names - just not as the first character before a Capital - and it's extremely useful. You won't get sent to Azkaban prison if do you use a $ character!
Webel electronics modelling recipe for SysML: Diagrams can be made less verbose by using stereotype icon shape display mode, by not showing names and types on obvious Ports, by hiding context-specific values, and by omitting {net} tagged values.
UML2/SysML1.x: If AggregationKind 'shared' has meaning to you (and if you use it consistently without contradicting the use of 'composite' aggregation elsewhere in your model) by all means use it. Damn the purists! But it's going to die in SysMLv2 anyway.
SysML: Having a Behavior owned by a Block it is allocated to may undermine purist functional allocation (because it presupposes the element of the physical solution that carries out the function)
UML/SysML: In Internal Block Diagrams: If you have a Port with a name that indicates a unique role AND and if there is an ItemFlow on a Connector that implies or suggests the Type of the Port, consider hiding the Type on the Port symbol.
Not every task in Activity Diagrams is well-suited to graphical modelling; consider using Action Language Helper (ALH) or Action Language for Foundational UML (Alf)
Not every task in Activity Diagrams is well-suited to graphical modelling and LoopNode and ConditionalNode are notoriously fiddly to setup; consider using Action Language Helper (ALH) or Action Language for Foundational UML (Alf)
MagicDraw: Has an additional tool-specific notation and feature sometimes called "ball-and-socket dependency wiring" for use with provided and required Interfaces in Class Diagrams and some other definition-level diagrams.
The default display of all tagged values on the comment symbol for an ElementGroup can make diagrams cluttered, but you can extend it with a custom stereotype and customise the default visible tagged values.
Verbose block property names and port names can help tracing participation of properties and ports in requirements relationships and play nicely with current SysML callout style.
Use of 'this-that' with a hyphen in Connector names is admissable (where 'this' and 'that' indicate Connector ends or their types)
If you are using model queries (such as table and report extraction) you may not always be able to use anonymous Property names and anonymous instance level element names
In SysML diagrams, showing the context name and type in the diagram frame can lead to clutter and is not always clear to non-SysML stakeholders (although that is the style used in the specification samples)
