I can’t say enough good things about the gear planner at
ddo-gear-planner.netlify.app
I love this gear planner, although some of the coloring throws me off sometimes. On the full list of gearing, green means highest level of the effect, blue and orange are duplicate effects - I think blue is a tie, and orange is usually a lower value, but I don't think it's always 100% accurate, especially for oddball effects that partially overlap like physical sheltering and sheltering. It’s almost impossible to avoid duplicate effects, especially when going for multiple sets.
When you click on an item such as your belt, a pop-up list of various belts is shown, sorted based on the effects you want, with purple color for effects you want and orange for effects you want but for which you already have a better version slotted. Sometimes, you won’t see the name of an item you want show up in the list of suggestions, so you still need to know what effects are possible, and some idea of key items you might want to slot. Then just type in the name to get it to show up.
The killer feature for me in using this planner is going down the page to the tables of tracked affixes and clicking on things like the various types of your main stat, especially enhancement, insight, and quality. You're more likely to get artifact and profane from a set bonus, and festive + exceptional from an augment. Using Constitution as an example, you will see "enhancement (15)", which means the highest available value is 15. A list of gear with Constitution will pop up when you click it with item names, ML, and slot, and you can see what type of tetris you're going to need to do in order to maximize your main stat.
Minor artifacts show up with yellow names when equipped on the main Equipment list, but not in the pop-ups, so be sure to check occasionally. I've happily made a wicked gearset a few times, only to realize that I had more than one artifact. [sad trombone noise]
You can pick the list of item effects you want on the first page, and can add affixes at the bottom of the second page if you forgot any.
There is a button to copy the equipment list to your computer's clipboard. I'll also copy and paste the entire link into my notes. The link is really long since it includes the affixes and slotted gear, but it makes life easier when I have to tweak a gearset later.
There is a definite learning curve, but I'll use this at cap every life, and sometimes when regearing at mid levels like 15 and 20.