List of Śikṣā Texts

General Śikṣā

Pāṇinīya Śikṣā (857)
Vedanāsikā Śikṣā or Vedāṅganāsikā Śikṣā (1168) (names of the Pāṇinīya Śikṣā in some Mss.)

Śikṣās related to Ṛgveda

Mādhusūdanī Śikṣā (949) (= Aṣṭa-vikṛti-vivṛti (123))
Vyāla Śikṣā (1247)
Vyāli Śikṣā (1) (1248) (= Aṣṭa-vikṛti-vivṛti (123))
Vyāli Śikṣā (2) (1249)
Śamāna Śikṣā (= Ṛksarva-śamāna (239); manuscripts MD 977?&978 call it Śamāna Śikṣā)
Śaiśirīya Śikṣā (1325)
Śaunaka or Śaunakīya Śikṣā (1328)
Svaravyañjana Śikṣā (1565)
Svarāṅkuśa (Śikṣā) or Svaranirṇaya (1584)
Hayagrīva Śikṣā (1602) (=Jaṭā-paṭala (599); generally attributed to Hayagrīva)

Śikṣās related to Sāmaveda

Gautama or Gautamī(-ya) Śikṣā (526)
Nārada or Nāradīya Śikṣā (755)
Lomaśa(śī) Śikṣā (1067)
Sāmaveda Śikṣā (1472) (*)

Śikṣās related to Śukla-Yajurveda

Amareśa Śikṣā (77) or Varṇaratnapradīpikā  Śikṣā (1099)
Amoghānandinī Śikṣā (1) (79) (130 verses)
Amoghānandinī Śikṣā (2) (80) (57 verses)
Avasānanirṇaya Śikṣā (107)
Kātyāyana (ī) Śikṣā (453) (13 verses)
Kātyāyana (ī) Śikṣā (454) (11 verses)
Keśava (vī) Śikṣā  (467) (Gloss on 9 Sūtras called Paribhāṣāṅka Sūtra)
Keśava (vī) Padyātmikā Śikṣā (468)
Kauśikī Śikṣā (478)
Kramakārikā Śikṣā (482) (also called Kāṇva Śikṣā (446))
Kramasaṁdhāna (Śikṣā) (506)
Galadṛk Śikṣā or Luptark Śikṣā (514) (= second part of Mādhyandinī Śikṣā (972))
Pārāśarī Śikṣā (869)
Prātiśākhyapradīpa Śikṣā (908)
Manaḥsvāra Śikṣā (951)
Mallaśarma Śikṣā or Hastasvaraprakriyā (957)
Māṇḍavya (vī) Śikṣā (958)
Mādhyandinī(ya) Śikṣā (972)
Yājñavalkya Śikṣā (1026)  (also called Vājasaneyi Śikṣā in a few Mss.)
Laghumādhyandinīya Śikṣā (1060)
Laghvamoghānandinī Śikṣā (1064)
Varṇaratnapradīpikā  Śikṣā (1099) or Amareśa Śikṣā (77)
Vāsiṣṭhī Śikṣā (1137)
Vedaparibhāṣākārikā Śikṣā (1174)
Vedaparibhāṣāsūtra Śikṣā (1176) (=Baiṭhasaṁjñakaprakaraṇa (937)
Ṣoḍaśaśloka Śikṣā (1338) (RV? or KYV?)
Saṁpradāyaprabodhinī Śikṣā (1401) (*) 
Svarabhaktilakṣaṇa (pariśiṣṭa) Śikṣā (1539)
Svarāṣṭaka Śikṣā (1599)

Śikṣās related to Kṛṣṇa-Yajurveda

Ātreya Śikṣā (1) (139) (27 verses)
Ātreya Śikṣā (2) (141) (294 verses)
Āpiśali Śikṣā (-Sūtra) (147)
Āraṇya (ka) Śikṣā  (152)
Kālanirṇaya Śikṣā (460)
Kauṇḍinya Śikṣā (1) (472) (100 verses)
Kauṇḍinya Śikṣā (2) (473) (86 verses)
Kauhalīya or Kauhala Śikṣā (479)
Cārāyaṇīya Śikṣā (550)
Bhāradvāja Śikṣā (943)
Pāri Śikṣā (870)
Pluta Śikṣā (917)
Yohiprāpti (Śikṣā) (1027)
Lakṣmīkānta Śikṣā or Catuḥślokī (1055)
Lakṣmīkānta Śikṣā  (1056) (= Uccasvaranirṇaya (178); Svara Śikṣā (1569))
Laugākṣi Śikṣā (1068) (= Śikhyā Pāṭha (1287))
Vararuci Śikṣā (1069)
Vāsiṣṭha Śikṣā (1) (1135) (on the doubling of consonants)
Vāsiṣṭha Śikṣā (2) (1136) 
Veda Śikṣā (1215)
Vyāsa Śikṣā  (1250)
Śambhu Śikṣā (1204)
Śikṣāsamuccaya (1303) (*)
Śyāmāyanīya Śikṣā (1332) 
Sarvasaṃmata Śikṣā (1409)
Svarasārabhūtavarṇa Śikṣā (1085; catalogued as Varṇa-Krama-Lakṣaṇam, Mysore P4772/22)
Siddhānta Śikṣā (1493)
Svara Śikṣā (1570)

Śikṣās related to Atharvaveda

Māṇḍukī Śikṣā (959)

Other Śikṣās

Atharva(ṇa) Śikṣā (27) (*)
Aniṅgya Śikṣā (40) (*)
Ācarya Śikṣā (138) (*)
Krama Śikṣā (502) (*)
Jaṭāmaṇi Śikṣā (609) (*)
Dvādaśa Śikṣā (720) (*)
Piṇḍalakṣaṇa Śikṣā (877) (*)
Varṇa Śikṣā (edited by Peter Freund)
Varṇaśikṣāsaṁhitā (1103) (*)
Varṇoccāraṇa Śikṣā (1112) (It includes the supposed Sūtra version of the Pāṇinīya Śikṣā) (*)
Śaṁkara Śikṣā (1252) (*)
Samāsa Śikṣā (1400) (*)
Sarvaśikṣāsaṁgraha (1407) (*)
Svaravigrahaśikṣābhāṣya (1559) (*)

Śikṣās not yet discovered

Agastya Śikṣā (8)
Audavraji Śikṣā ?
Bodhāyana Śikṣā (939) (KYV)
Plākṣi Śikṣā (913)
Vālmīki Śikṣā (1134) (KYV)
Hārīta Śikṣā (1613) (KYV)

Lists of Śikṣākāras and works on Vedalakṣaṇa

Vedalakṣaṇānukramaṇikā (1207) (*)
Śikṣādivedāṅgasūcī (1284)

Notes:

1. Source: "Veda-Lakṣaṇa, Vedic Ancillary Literature, A Descriptive Bibliography" compiled by K.P. Aithal

2. Only those texts have been included which are generally or occasionally called Śikṣā.

3. Links:   
http://detlef108.blogspot.de/2014/11/siksa-links.html

All Śikṣās except those marked with (*) are available on
https://vedicreserve.miu.edu/shiksha/shiksha_vedicreserve.html
http://peterffreund.com/shiksha/shiksha.html
http://peterffreund.com/manuscripts/Recent_Additions.html