These are the steps I took to create my first template with the layout and module positions I want. Based on the Gantry5 Helium Theme. These are not instructions but someone might find it useful if you are going through the same thought process.

Step 1

• Remember it is a blank template
• Do fresh install of gantry
• Think of a template name (Lancastrian)
• Clone/duplicate base outline, no inheritance
• Set as default Joomla template
• Plan your sections, how you want then on paper
• Edit the layout.yaml of the outline to configure your sections on how you want them
• Change the name in the .yaml (word auto capitalizes, - are changed to spaces)
• Add modules, module positions and particles however you want them
• Edit particle defaults in base outline, styles page, page settings, can do in .yaml file but in admin is easier
• Make a list of new sections (over the base outline)
• Make a list of sections to be removed (over the base outline)
• Copy helium.scss to override location
• Remove unneeded sections (optional)
• Disable admin settings via blank .yaml
• Component out css in helium.scss override or rebuild new stack leaving old one commented out
• You can first add new sections below but the current default theme is very messy
• Add new sections
• Helium CSS already has a new section stack
• Create SCSS for new sections in custom/scss/helium/sections…. Only for the new ones or any that you want to override, only if you want to style it
• Make sure you take relevant styling (i.e. aside) and place in the new ones
• Create admin sections for these optional
• Disable admin sections by adding blank .yaml files for the no-longer needed sections /custom/blueprints/styles/.yaml
  
  this causes a new section to be made. Can I disable them in gantry. These will go when I change the default base outline
• NB: you could copy all SCAA files then you know what to work on
• Copy SCSS + create for new
• Copy CSS for aside , sidebar, only override altered code
• Add admin sections for the new sections
• take header styles and use that file to create
• create blank files for the new sections /blueprints/styles/sections
• the .yaml input files must match the code in the SCSS files. so decide how you want them to look what “sections ?” maybe first basic section
• what defaults create the new sections with the code from the nearest section and then get the corresponding SCSS code in the right file with references changed as needed.
• Copy aside and sidebar into yaml
• There is no yaml for aside and sidebar but there is a SCSS
• Add styling for the main container > sidebar + aside
• I will override header so it is standard and make all the sections standard as well (features section). Actually I will leave the header as is because it shows me options and I do not have to use them. The rest I copy features section
• I used the features section .yaml and SCSS to make all my sections plain and simple. I can alter them later if needed
• The defaults are what are rendered
• You can use $base-container in other yaml (these variables are like php variables, cross file)
• So I have first done the sections styling and admin sections
• Add custom SCSS /custom/SCSS/custom.scss
• With the nav pills fix in it

Step 2

• Check for errors
• overriding the helium file causes issues = my fault
• I had not added _mainnav.scss which styles the menu

Step 3

• Override the default. This should make all other sections disappear.
• Don’t delete particles folder.
• The admin section for the other sections are still there
• Move the original defaults somewhere safe
• Copy your template files into default
• Recreate the default outline (inherit all)
• You can edit on the base outline and all changes will be reflected in the default outline

Step 4

• Look at how to remove admin sections will yaml overrides. Could still use as is but there is a weired section at the bottom

Step 5

• When backup, delete the standalone template as it is no longer neeed
• Aside and sidebar module positions still exist
• Need to be able to set content-right to max 25% width and main content fills the rest. This setting will not be inherited, I thing it is a bug
• Develop the Lancastrian theme as a separate theme (not default), re-enable particle defaults via hack