As you know "Shree Lakshmi-Tantra" has an extremely ample set of Shree MahaLakshmi Mantras.
For example, my current sadhana consists of 13 Mantras of Shreemati MahaLakshmi-Devi ("13" is my lucky number).
You can use an ordinary notepad just striking out The Mantras you have recited, but I use "GoogleKeep" on my Android-phone, because it has great list system with striking out and copy!
I can't reveal my Shree MahaLakshmi-Mantras, so the following example demonstrates Shree Durga-Mantras from श्री चामुण्डेश्वरी अष्टोत्तरशतनामावलिः - "ShrI ChAmuNDEshvarI AShTottarashataNAmAvaliH"
1. So, for example, there are 6 Mantras of Shreemati Durga-Devi in your sadhana. Use bulleted note and type The Mantras manually in the list. I strongly recommend to type with digits - 01. 02. and etc., please see the picture below:
2. After you repeat, let's say, Mantras 04 and 05 (108 times on Rudraksha beads), you just strike out points 04 and 05 from the list:
3. Embellishing the techique with "COPY". The great feature of "GoogleKeep" is "Copy", so you can copy you list of Mantras for example 7 times (for 7 subsequent days of the week). "COPY"-option is usually on the top-right (but can be on top-down on some phones):
4. This is the example of 9 squares with Shree Durga-Mantras, 1 square (set of Mantras) per day:
Vishnudut1926, Moscow, February 2017