Whomever told you that 'loops' were difficult to tie must've been trying to sell you some overpriced loops.
What?
Have you been talking to Mesika again?
Relax people...kidding.
Anyway, loops are easy to tie and since you can get IT or IET very inexpensively (don't get it at a 'magic store'), it only makes sense that you tie your own.
Here's a link for you:
https://www.youtube.com/watch?v=dkpu26hGusk
At the 4:38 mark, the author uses regular string so that you can see exactly how to tie the invisible thread.
If you'd prefer a different vid, just do a quick search.