I build everything in 1:1 scale on ZEN METAL. This means that I equate one real life meter directly to one Second Life meter. (Usually, creators don’t do this.) While I fit my own scenes quite beautifully, sometimes I feel too small elsewhere on Second Life, even though I don’t usually let it bother me.
Still, for the moments that it bothers me, I keep two shapes in my inventory and keep an upscaled version of unrigged clothing parts that I wear a lot in a separate “big me” outfit folder. (You have to edit it through the Inventory, rather than the Outfits window, but I’m not going to explain it further just now. You could also keep a copy of “big parts” or “small parts” in an inventory folder.)
With rigged outfits and hair, it’s usually quite simple to switch between shapes without drama. However, unrigged items become a problem. In other words, you’ll have to manually adjust their position, and that position will be saved into the object, NOT into the outfits inventory folder information. Therefore, you should keep two copies of items you wear between shapes.
Personally, I also keep a quick-change version of a clothing style that I predict I might need to swap into depending on the sim I’m on in my Outfits: Big Me Formal, Big Me Casual, Big Me Business, Big Me Beach, and in the picture, Pretty Ordinary Big Me, which is kind of my most default outfit based on my real life style. This usually suffices for me, as I rarely bother switching to big shapes, and small girls are acceptable things to see around.
This way, I’m never too bothered about my size, even though I choose to play in 1:1 scale whenever I can.
As you can see, it’s really difficult to say which one of the avatars is “real size” without anything surrounding them. You might notice the “big me” has too small feet, as the Lara feet don’t usually scale in shoes. So for practical reasons, your foot size must set to 0 if you want to wear and change shoes… (The screencaps have been taken without altering camera position to make the comparison absolute.) That said, the normal sized avatar looks like a teen ager with her mom, when side-by-side. No wonder, given that “mom” is as tall as Ru Paul!