The basic homa of subrahmanya, practiced by shrIvidyA upAsakas is based on vasistha samhitA and involves the worship of subrahmaNya in two forms: saguNa and nirguNa. After performing the shaDAvaraNa pUja of subrahmaNya, homa is performed first with subrahmanya shaDakSharI mantra and then with subrahmaNya panchadashAkSharI mantra. This is followed by shaDAvaraNa pUja of the great brahmaNya and homa with the aShTAdashAkSharI mantra of the nirguNa swarUpa, followed by dashAmsha Ahutis to anga mantras including the mahAvAkyas .
kArtikeya homa, detailed in guhArchanachandrikA involves a basic homa with the vimshatyakshara kArtikeya mantra, followed by a dashamsha Ahuti of the well-known ShaDakSharI. This forms the prologue and is followed by the shatrusamhAra trishatI homa. The eighteen weapons of kArtikeya are first offered oblations with their respective mantras, and Ahutis are offered to icchA shakti & jnAna shakti i.e. vallI and devasenA with their six yoginI shakti-s [trailokyavijayA, trailokyasanjIvinI, trailokyadraviNI etc.]. Ahutis are then offered to the three velAyudha-s, pancha brahma mUrti-s, Ashu garuDa, vIrabhadra, bhadrakAlI, gAruDanrsimha and finally with the 300 names. samputIkaraNa vidhi for the 300 names is a vast subject in itself. Dravya vishesha to be used for this homa is also specifically detailed.
Guha homa paddhati  involves basic homa with the mUla mantra of guha, followed by dashAmsha homa with malA mantra, sanakAdi chatuShTaya mantras, kukkuTa, shaktyAyudha, mayUra, vetAla and sharabhakAlikA mantras. kumara homa involves homa with kumara mantra, along with Ahutis for various mUrtis such as jnAna brahmanya, skanda, guha, agnisambhava, sharavaNa, deshikesha, kraunchachedana, shaNmukha, krodhonmatta, kalyANasundara, srShTidhAraNa etc. There is a specific paddhati detailed in akAshabhairava tantra for the worship of prasanna skanda mUrti, followed in kukke subrahmaNya kShetra.
Namo Namaste shiva kAmakoTI
 This Vasistha Samhita does not seem to the same as the one which is a part of shubhAgama panchaka. The almost complete version of vasisTha samhitA that I have seen does not include these details. The details of this homa, supposedly from vasistha samhitA, were taught to me by Sri Chandrashekharan Iyer of Trichy, who was a close disciple of H H Sri Shantananda Saraswati Mahaswamigal of Pudukkottai. An incomplete version of this vasistha samhitA, which includes the chapter dealing with subrahmaNya homa is present with mahAmahopAdhyAya R Satyanarayana. Also, uDDAmareshwara tantra, while describing the anga mantras of ramAdi ShoDashI, refers to the two mantras with the statement, `as discussed in 31st paTala before narrating Vasistha's conversation with Shakti'. Unfortunately, only the second half of this paTala is available to the best of my knowledge.
 shrI chidAnandanAtha of guhAnanda mandali taught an almost similar worship but with the position of two of the bIjas inter-changed in aShTAdashAkSharI. He however, did not advocate an actual agnimukha prayoga here but taught antaryAga involving swAdhiShThAna in place of the classical mUlAdhAra.
 guhArchanachandrikA is a work authored by a siddha yogi named appA svAmayyar. A version of this work was obtained from a disciple of this yogi in Rajamatangi's city, Sri Santana Gopalan, by our dear Sri S K Ramachandra Rao. He graciously gave me the original copy saying, `Anything for those belonging to Sri Chandrashekhara Bharati's lineage'. This is quite an emotional possession, as it was sort of his parting gift.
 Guha Homa paddhati was found in a hand written copy handed down through generations, which I copied from late Sri Gopalakrishna Dikshitar based in Chidambaram. Though it seems like a compilation, each of the forty chapters ends with the statement, `mahAkaumAra tantre, guhapaddhatau blah blah paTalaH' etc.