The Shulchan Aruch rules that one should always be in the habit of saying, "Everything the Merciful One does is for the best." (Orach Chaim 230:5; Berachos 60b). So we should say that throughout the day, whenever something happens. A shorter equivalent would be "gamzu l'tovah" from the Talmudic story of Nachum Gamzo. (Ta'anis 21a). Similarly, the Yerushalmi says that one should always say, "Lord of Hosts, Happy is the man who trusts in You." (Y. Berachos 5:1, 53b). This could have a similar effect, of reminding you to trust that Hashem is determining events, and doing everything for the best.
Another idea is to keep a "hashgacha pratis" journal, keeping daily notes of coincidences and other things that happen to you daily, which reinforce your belief in Providence. This could be as simple as an email you send yourself with a brief description, and whenever another thing happens, it can be a "Re:" email in response, helping you collect the recollections in one thread. Sooner or later, you will begin to notice such things on a daily basis.
Finally, see this passage on "hints" Hashem sends us, and read these two chapters (here and here) from the Bilvavi on Divine Providence.