What i say is the way its been before, things have changed now and i won't be telling you what i suspect simply because the way it changed to is retarded, and thats one of the reasons i dont want one anymore.
Some people still get tags "the all fashioned way" and it is that way i will explain.

You need 3 things:
1) Deserve a tag
2) Fit for one
3) Get noticed

You deserve a tag by needing it... i know some guild leaders who got trusted tags since they were very active in the level service field, others just been active traders, making literally hundreds of thousands FG transfers a month.
Someone who is very trusted in the community but makes 3-4 trades a day, meh not really needed, he can use a mediator.

You fit for one by being a generally good member. Obviously the mod team doesn't want people who flame / curse / act in a bad manner.
You should help where you can, this may include price checks for some, general help for others, or other different ways we all know.
Being a duper or connected to dupers is a reason to disqualify for a tag, since njaguar doesn't want the market on d2jsp to be flooded with dupes, that makes no one happy.

Getting noticed is the part that most people called "Ass licking", but its really the only way to do things.
Since d2jsp has tens of thousands active members, its impossible to just "notice" the active members, because we have only a small team to deal with this.
You get noticed by doing (1) and (2) and by socializing with members of the moderation team.
Every active member will eventually get to know a mod team member and make friends with him/her. Thats the natural course of things when you report violations / ask for help / whatever.
Getting noticed is NOT the same as sucking up. You need to understand that there are about 15-20 people who are able to request trusted tags, and they won't be choosing you when you sit on your ass and trade all day, even if thats the purpose of the tag.

Recently Reporting violations became an important part of getting noticed, but someone who reports a lot but doesn't trade at all doesn't really need a tag, and he prolly wont get it.