I call these "Irish Crochet-style" motifs because these are not, strictly speaking, Irish crochet. These motifs resemble popular Irish crochet motifs but these are crocheted without the padding cord. In this sense, these motifs are easier to make than traditional Irish crochet motifs. These motifs are based on patterns found in the Russian crochet-knit magazine series, Zhurnal Mod. Although the magazines are in Russian language, anyone who can read crochet symbols should be able to use the magazines.
If I remember correctly, I used 3-ply cotton yarn and 2.5mm hook to make these motifs. Here I include some photos of several pages from the magazines. If you are interested in buying some magazines for yourself, you can find the authorised on-line seller at http://www.duplet-crochet.com
Admittedly, Irish crochet motifs with the padding cord are much more beautiful because the padding cord brings out a much more apparent differences in the texture of the motifs and the 3-dimensional appearance that Irish crochet is most well-known for.