Sources: all collections; answered in English in the Scholarly style.

Segulot for Marriage

Intense Prayer [Likkutei Etzot, Marriage.1]: "Intense prayer can help a person to find his marriage partner" (citing Likutey Moharan I, 9).

Avoiding Robbery (negative warning) [Likkutei Etzot, Money and Livelihood.36]: גַּם לִפְעָמִים יְאַבֵּד הַגַּזְלָן בַּת זוּג שֶׁלּוֹ עַל־יְדֵי הַגְּזֵלָה — "Sometimes a thief loses his mate (בַּת זוּג) through robbery." Conversely, avoiding theft protects one's shidduch.

Segulot for Parnassah

Torah Study + Prayer [Sefer HaMiddot, Money, Part I.97]: מִי שֶׁאֵין לוֹ פַּרְנָסָה, יַעֲסֹק בַּתּוֹרָה וְאַחַר כָּךְ יִתְפַּלֵּל עַל פַּרְנָסָה, בְּוַדַּאי יִתְקַבֵּל תְּפִלָּתוֹ — "One who lacks livelihood should study Torah and then pray for livelihood; his prayer will certainly be accepted."

Intense Prayer [Likkutei Etzot, Money and Livelihood.3]: "Intense prayer makes one worthy of one's livelihood" (citing 9:2).

Charity [Likkutei Etzot, Money and Livelihood.1]: Pride, malicious gossip, and worthless pursuits cause poverty; "the remedy is to give charity, which brings blessing and prosperity." [Likkutei Etzot, Money and Livelihood.39]: לט — אִם רוֹאֶה אָדָם שֶׁמְּזוֹנוֹתָיו מְצֻמְצָמִין, יַעֲשֶׂה מֵהֶם צְדָקָה — "If a person sees his sustenance is tight, he should give from it as charity; through charity his money is rectified and he will have livelihood in abundance."

Mezuzah [Likkutei Etzot, Money and Livelihood.12]: "The mitzvah of mezuzah is a remedy against the lust for money. When you observe this mitzvah carefully your livelihood will fly into your hands!"

Humility [Likkutei Etzot, Money and Livelihood.43]: "When a person is meek and humble, no one can 'shift him from his place' in the sense of impinging on his livelihood."

Honest Business Dealings [Likkutei Etzot, Money and Livelihood.44]: עַל־יְדֵי מַשָּׂא וּמַתָּן בֶּאֱמוּנָה — "Through conducting business faithfully one fulfills 'And you shall love…'; through this he will have livelihood without toil and hardship."

Joy in Torah and Mitzvot [Likkutei Etzot, Money and Livelihood.51]: עַל־יְדֵי שִׂמְחַת תּוֹרָה וּמִצְוָה עַד שֶׁמְּרַקֵּד מֵחֲמַת שִׂמְחָה, עַל־יְדֵי זֶה הָאָדָם נִתְעַלֶּה בְּמָמוֹן — "Through joy in Torah and mitzvah to the point of dancing, a person is elevated in wealth" (citing Likkutei Torah §81).

Avoiding Treifot [Likkutei Etzot, Money and Livelihood.24]: כְּשֶׁיִּשְׂרָאֵל שׁוֹמְרִין אֶת עַצְמָן מִטְּרֵפוֹת, עַל־יְדֵי זֶה יֵשׁ לָהֶם פַּרְנָסָה — "When Israel guard themselves from non-kosher food, through this they have livelihood."

Avoiding Immorality [Likkutei Etzot, Money and Livelihood.2]: "Immorality can deprive a person of his livelihood" (citing 7:5). Guarding oneself from this is thus a segulah for parnassah.

Guarding the Brit [Likkutei Etzot, Money and Livelihood.4]: מְרִירַת וִיגִיעַת הַפַּרְנָסָה הוּא כְּפִי פְּגַם הַבְּרִית — "The bitterness and toil of earning a livelihood corresponds to the blemish of the covenant (פְּגַם הַבְּרִית)." Guarding the brit eases parnassah.

References

1. Likkutei Etzot, Marriage.1
2. Likkutei Etzot, Money and Livelihood.3
3. Likkutei Etzot, Money and Livelihood.43
4. Likkutei Etzot, Money and Livelihood.12
5. Likkutei Etzot, Money and Livelihood.1
6. Sefer HaMiddot, Money, Part I.97
7. Likutei Moharan, Part II.5:3:4
8. Peninei Halakhah, Simchat Habayit U'Virkhato, .5:7:5
9. Likkutei Etzot, Money and Livelihood.40
10. Likkutei Etzot, Money and Livelihood.51
11. Likkutei Etzot, Money and Livelihood.39
12. Likkutei Etzot, Money and Livelihood.36
13. Likkutei Etzot, Money and Livelihood.45
14. Likkutei Etzot, Money and Livelihood.42
15. Likkutei Etzot, Money and Livelihood.4
16. Likkutei Etzot, Money and Livelihood.25
17. Likkutei Etzot, Money and Livelihood.24
18. Likkutei Etzot, Money and Livelihood.35
19. Likkutei Etzot, Money and Livelihood.2
20. Shulchan Arukh, Even HaEzer, .47:1
21. Likkutei Etzot, Money and Livelihood.41
22. Likkutei Etzot, Money and Livelihood.44
23. Likutei Moharan, Part II.16:3:2
24. Bereshit Rabbah.20:9
25. Likutei Moharan, Part II.7:10:11