There is a practice among some to kiss the tzitzit at certain points during davening (related questions abound). The Shulchan Aruch in one place (O"C, 24:5) says that the person should be looking at the tztitzit that are in front of him because they have a certain number of knots etc. כְּשֶׁמִּסְתַּכֵּל בַּצִּיצִיּוֹת מִסְתַּכֵּל בְּב' צִיצִיּוֹת שֶׁלְּפָנָיו, שֶׁיֵּשׁ בָּהֶם עֲשָׂרָה קְשָׁרִים, רֶמֶז לַהֲוָיוֹת. וְגַם יֵשׁ בָּהֶם ט''ז חוּטִים וַעֲשָׂרָה קְשָׁרִים עוֹלוֹת כ''ו כְּשֵׁם הַהֲוָיָה
However, the O"C in 8:12 also states "אִם יֵשׁ לוֹ כַּמָּה בְּגָדִים שֶׁל אַרְבַּע כְּנָפוֹת כֻּלָּם חַיָּבִים בְּצִיצִית. וְאִם לְבָשָׁם כֻּלָּם בְּלֹא הֶפְסֵק וְהָיָה דַּעְתּוֹ מִתְּחִלָּה עַל כֻּלָּם, לֹא יְבָרֵךְ אֶלָּא בְּרָכָה אַחַת" If one has many four cornered garments, all of them are obligated to have fringes. And if one puts them all on without a break, and has in mind from the beginning about all of them, he only makes a single blessing
This happens to me when I wear both a talit katan and a talit gadol.
When I wear both, I have four tzitziyot in front of me -- which ones am I supposed to hold (and kiss?)? And if I have even more garments, should I be taking the front tzitzityot from only one of them (so that the numbers referenced above hold true) and if so, which one, or all of them because they are all equally important?