Śrīla Rūpa Goswāmī explains how to practice Rāgānugā-sādhana, in three verses of Bhakti-Rasāmṛta-Sindhu (1.2.294-296):
kṛṣṇaṁ smaran janaṁ cāsya preṣṭhaṁ nija-samihitam
tat-tat-kathā-rataś cāsau kuryād vāsaṁ vraje sadā
“Remember Krishna with his beloved devotee whose love for Krishna exemplifies your own aspirations. Dwell there in Vṛndāvana by always discussing them and their love.”
sevā sādhaka-rūpeṇa siddha-rūpeṇa cātra hi
tad-bhāva-līpsunā kāryā vraja-lokānusārataḥ
“Emulate the essence of the Vṛndāvana-bhāva you adore, by executing the practical forms of devotional service with relevance to their prefect forms.”
śravaṇot-kīrtanādīni vaidha-bhakty uditāni tu
yāny angāni ca tany atra vijñeyāni manīṣibhiḥ
“The wise know that the practices of Vaidhi-bhakti previously described, especially those beginning with hearing and chanting, are the practical forms of devotional service to be executed.”
Here are important points I would like to clarify.
From the first verse:
(1) We need a clear aspiration for a specific relationship with Krishna before we can begin.
(2) Three things should always be remembered: Krishna in the form that we adore, the devotee whose love exemplifies what we aspire for, and the intimate relationship between Krishna and that devotee.
(3) Smarana (rememberence of these three) is the essence of Rāgānugā, but this smarana is based on kīrtana (kathā)
(4) By doing kīrtan of these three things we become absorbed in memory of them and thus live in Vṛndāvana. To physically live in Vṛndāvana is also very important (one of the five most powerful spiritual practices) but its not what Śrī Rūpa is talking about here. Rāgānugā can be practiced outside Vṛndāvana-Mathurā. Mahāprabhu, for example, practiced it in Jagannātha Puri.
From the second verse:
(1) The first verse was what Śrī Bhaktivinoda would probably identify as śravaṇa-daśa. This second verse is what he would probably call varaṇa-daśā.
(2) We should engage in devotional service (seva).
(3) The devotional service has two forms, a practical form (sādhaka-rūpeṇa) and a perfect form (siddha-rūpeṇa). We have to engage in service in both ways. Not just externally (sādhaka-rūpa), and also not just internally (siddha-rūpa).
(4) We do this be correlating the external activity to a perfect activity performed by the Vrajabāsī whose relationship with Krishna exemplifies what we aspire for. (the whole second line explains this).
From the third verse:
(1) If we ask the second verse, “You said to do devotional service (seva)… what devotional service should we do?” The answer is the third verse: the practices defined when discussing vaidhi-sādhana are the devotional service the rāgānugā-sādhaka should engage in. Especially those that are based mostly on hearing and chanting.
(2) If we ask, “Then how is it different from vaidhi-sādhana, the answer is in the first and second verses.
— Vraja Kishor dās